py3: fix display of default user permissions

Avoid http://localhost:5000/vcs_test_hg/settings/permissions with explicit user
permissions failing:

  TypeError: '<' not supported between instances of 'str' and 'bool'

kallithea/templates/admin/repos/repo_edit_permissions.html

@@ -1,107 +1,107 b''
 ${h.form(url('edit_repo_perms_update', repo_name=c.repo_name))}
 <div class="form">
         <div class="form-group">
             ${h.hidden('repo_private')}
             <table id="permissions_manage" class="table table-condensed">
                 <tr>
                     <td>${_('None')}</td>
                     <td>${_('Read')}</td>
                     <td>${_('Write')}</td>
                     <td>${_('Admin')}</td>
                     <td>${_('User/User Group')}</td>
                     <td></td>
                 </tr>
                 ## USERS
-                %for r2p in sorted(c.repo_info.repo_to_perm, key=lambda x: x.user.username != 'default' and x.user.username):
+                %for r2p in sorted(c.repo_info.repo_to_perm, key=lambda x: '' if x.user.username == 'default' else x.user.username):
                     %if r2p.user.username =='default' and c.repo_info.private:
                         <tr>
                             <td colspan="4">
                                 <span class="private_repo_msg">
                                 ${_('Private Repository')}
                                 </span>
                             </td>
                             <td class="private_repo_msg"><i class="icon-user"></i>${_('Default')}</td>
                         </tr>
                     %else:
                     <tr id="id${id(r2p.user.username)}">
                         <td>${h.radio('u_perm_%s' % r2p.user.username,'repository.none')}</td>
                         <td>${h.radio('u_perm_%s' % r2p.user.username,'repository.read')}</td>
                         <td>${h.radio('u_perm_%s' % r2p.user.username,'repository.write')}</td>
                         <td>${h.radio('u_perm_%s' % r2p.user.username,'repository.admin')}</td>
                         <td>
                             ${h.gravatar(r2p.user.email, size=14)}
                             %if h.HasPermissionAny('hg.admin')() and r2p.user.username != 'default':
                              <a href="${h.url('edit_user',id=r2p.user.user_id)}">${r2p.user.username}</a>
                             %else:
                              ${r2p.user.username if r2p.user.username != 'default' else _('Default')}
                             %endif
                         </td>
                         <td>
                           %if r2p.user.username !='default':
                             <button type="button" class="btn btn-default btn-xs" onclick="ajaxActionRevoke(${r2p.user.user_id}, 'user', '${'id%s'%id(r2p.user.username)}', '${r2p.user.username}')">
                             <i class="icon-minus-circled"></i>${_('Revoke')}
                             </button>
                           %endif
                         </td>
                     </tr>
                     %endif
                 %endfor
 
                 ## USER GROUPS
                 %for g2p in sorted(c.repo_info.users_group_to_perm, key=lambda x:x.users_group.users_group_name):
                     <tr id="id${id(g2p.users_group.users_group_name)}">
                         <td>${h.radio('g_perm_%s' % g2p.users_group.users_group_name,'repository.none')}</td>
                         <td>${h.radio('g_perm_%s' % g2p.users_group.users_group_name,'repository.read')}</td>
                         <td>${h.radio('g_perm_%s' % g2p.users_group.users_group_name,'repository.write')}</td>
                         <td>${h.radio('g_perm_%s' % g2p.users_group.users_group_name,'repository.admin')}</td>
                         <td>
                             <i class="icon-users"></i>
                             %if h.HasPermissionAny('hg.admin')():
                              <a href="${h.url('edit_users_group',id=g2p.users_group.users_group_id)}">${g2p.users_group.users_group_name}</a>
                             %else:
                              ${g2p.users_group.users_group_name}
                             %endif
                         </td>
                         <td>
                             <button type="button" class="btn btn-default btn-xs" onclick="ajaxActionRevoke(${g2p.users_group.users_group_id}, 'user_group', '${'id%s'%id(g2p.users_group.users_group_name)}', '${g2p.users_group.users_group_name}')">
                             <i class="icon-minus-circled"></i>${_('Revoke')}
                             </button>
                         </td>
                     </tr>
                 %endfor
                 ## New entries added by addPermAction here.
                 <tr class="new_members last_new_member" id="add_perm_input"><td colspan="6"></td></tr>
                 <tr>
                     <td colspan="6">
                         <button type="button" id="add_perm" class="btn btn-link btn-xs">
                             <i class="icon-plus"></i>${_('Add new')}
                         </button>
                     </td>
                 </tr>
             </table>
         </div>
         <div class="form-group">
             ${h.submit('save',_('Save'),class_="btn btn-default")}
             ${h.reset('reset',_('Reset'),class_="btn btn-default")}
         </div>
 </div>
 ${h.end_form()}
 
 <script>'use strict';
     function ajaxActionRevoke(obj_id, obj_type, field_id, obj_name) {
         let url = ${h.js(h.url('edit_repo_perms_revoke',repo_name=c.repo_name))};
         var revoke_msg = _TM['Confirm to revoke permission for {0}: {1} ?'].format(obj_type.replace('_', ' '), obj_name);
         if (confirm(revoke_msg)){
             ajaxActionRevokePermission(url, obj_id, obj_type, field_id);
         }
     }
 
     $(document).ready(function () {
         if (!$('#perm_new_member_name').hasClass('error')) {
             $('#add_perm_input').hide();
         }
         $('#add_perm').click(function () {
             addPermAction('repository');
         });
     });
 </script>