rm $wgCountTotalSearchHits. It was broken.

If $wgCountTotalSearchHits was set to true, then the total
number of hits returned was zero, which caused Special:Search
to display no results.

I'm opting to remove the feature (although I don't have any
strong opinions about removal vs changing Special:Search), since
if someone both cares about performance and has a wiki where its
big enough to matter, they are going to need to use Cirrus anyways.

Change-Id: I1c3b908ae5423ce3dfbdc22b1a68dd81a85698aa
Merge "rm $wgCountTotalSearchHits. It was broken."