Update LocalSettings.php

Follow up to commit https://github.com/thingles/wiki-farm/commit/16300328fe84736ede3cc6fad22ed82a43d9c9d8 related to issue https://github.com/WikiApiary/WikiApiary/issues/200
Merge pull request #4 from kghbln/patch-2

Group name error fix from @kghbln.