[#30929] fix JHtmlQuery::suggested()

Fixing issue described in [bug #30929](http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_id=8103&tracker_item_id=30929), related a case sensitive alternative search terms creation (components/com_finder/helpers/html/query.php)
Merge pull request #3265 from itbra/patch-9

[#30929] fix JHtmlQuery::suggested()