[#33432] Mod Menu as "sidenav" - for Joomla! 2.5

Changed condition in mod_menu/helper.php to allow show menu items from lover levels of active menu item.

This allow use module mod_menu as "side-navigation" because you can now see menu items under active parent menu item.

Tracker: [#33432] http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=33432&start=650