For https://en.wikipedia.org/wiki/Wikipedia_talk:AutoWikiBrowser/Bugs#Duplicated_cat_with_same_sortkey_was_not_removed

git-svn-id: svn://svn.code.sf.net/p/autowikibrowser/code/AWB@10242 5227b50d-9349-4574-b055-4b0a7525e11c