(bug 13693) Categories sometimes claim to have a negative number of members. Just...

(bug 13693) Categories sometimes claim to have a negative number of members.  Just recount them in this case; they *should* have relatively few members, so it should be fast.  Note that even a worst-case scenario (recount of enwiki Living people) takes only a few seconds on the cluster, and it seems incredibly unlikely that that would occur.