Updated mediawiki/extensions
Project: mediawiki/extensions/CentralNotice  9816546bff358cd0c7c29559b2968c6011fe89c3

Only register and assign "centralnotice-admin" if needed

These rights are only needed on wikis that allow editing
CentralNotice related things, so only add them there.

Change-Id: I375270e5b6e688a72ec01ff9e4e018ecaaf94980