(minor) remove check for user.isAnon. Should always be set now

Since the dependency to 'mediawiki.user' has been added, this check is rather pointless. If this check would ever the true, something else must be wrong and we want to get notified by an error.

Change-Id: Id12ea100efec9848f2c425c2675ba955c6a9ecfe
Merge "(minor) remove check for user.isAnon. Should always be set now"