[#33180] Smart search filter can't list non-Latin categories

See http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=33180&start=0

To test, create a category with non latin glyphs (For example: பன்-மொழி உதவிக்குறிப்புகள் )and an item in the category.
Then Index in SmartSearch.
Then Create a new filter in Smart Search: in the category dropdown, the new category will display as "All"

Patch and retest