Allow to add/remove the autoreview group on mediawiki.org

This is needed to give "autopatrol" permission to users; sysops and
bureaucrats lost this ability when FlaggedRevs was removed in
I6d3a71b0a (04bf775f92857).

Change-Id: I8ad0a00cee05d28d0349bafd537c28ed8a82e2d7
Merge "Allow to add/remove the autoreview group on mediawiki.org"