user groups: fix form and label

rhodecode/templates/admin/users/user_edit_groups.mako

@@ -6,15 +6,17 b''
       <h3 class="panel-title">${_('User groups administration')}</h3>
     </div>
     <div class="panel-body">
+        <div class="fields">
         <div class="field">
             <div class="label label-checkbox">
-                <label for="users_group_active">${_('Add user to group')}:</label>
+                    <label for="users_group_active">${_('Add `%s` to user group') % c.user.username}:</label>
             </div>
             <div class="input">
                 ${h.text('add_user_to_group', placeholder="user group name", class_="medium")}
             </div>
 
         </div>
+        </div>
 
         <div class="groups_management">
             ${h.secure_form(h.route_path('edit_user_groups_management_updates', user_id=c.user.user_id), method='post')}