CategoryViewer: Do opportunistic category recounts for mismatched file counts, too

CategoryViewer: Do opportunistic category recounts for mismatched file counts, too

There are some categories on Commons that have no files, but are
recorded to have some, e.g. [1] appears to have 15 files [2]. We have
logic to fix these, but it wasn't being checked for file counts (only
pages and subcats).

[1] https://commons.wikimedia.org/wiki/Category:Police_of_Mexico,_D._F._vehicles
[2] https://commons.wikimedia.org/w/index.php?title=Category:Police_of_Mexico,_D._F._vehicles&action=info

Change-Id: If88fc15347eb592e957452884c2179d7c237bd2c