[FIX] trackers: Filter search was broken - $ev was set here (which it should be by now) so text for empty instead (generally better)
Should close wish4774, thanks Nelson

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/12.x@48009 b456876b-0849-0410-b77d-98878d47e9d5