Allow bureaucrats to remove advanced permissions on wikimania2014wiki

By authority of James Forrester.

I added the seemingly redundant comment because what are the chances
someone will blindly copy-and-paste the 2014 settings for next year's
wikimania wiki? The whole process of spawning a new wiki annually is
stupid and needs to be rethought.

Bug: 55480
Change-Id: I6525a4b809b6b3e63aa0c6806fd9bbf3e75127fe