hide add repository button when you don't have at least write permission in group

ref  #730

rhodecode/templates/index_base.html

@@ -10,7 +10,9 b''
                 %if h.HasPermissionAny('hg.admin','hg.create.repository')():
                   <li>
                   %if c.group:
-                    <span>${h.link_to(_('Add repository'),h.url('admin_settings_create_repository',parent_group=c.group.group_id))}</span>
+                    %if h.HasReposGroupPermissionAny('group.write', 'group.admin')(c.group.group_name):
+                        <span>${h.link_to(_('Add repository'),h.url('admin_settings_create_repository',parent_group=c.group.group_id))}</span>
+                    %endif
                   %else:
                     <span>${h.link_to(_('Add repository'),h.url('admin_settings_create_repository'))}</span>
                   %endif