Fixcount: Fixed bug #31455: Regression on #31278: Improve counting of results in querie

Added condition that query that gets modified with COUNT(*) instead of loading all rows must not have any GROUP BY nor HAVING statement (and be of type 'select').

That fixes the bug #31455 : http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=31455
Which is a regression of fix #31278 : http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=31278