Fixed compiler warning (unused variable).

git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/trunk@5847 178a84e3-b1eb-0310-8ba1-8eac791a3b58

src/states_screens/tracks_screen.cpp

@@ -180,9 +180,6 @@ void TracksScreen::init()
     DynamicRibbonWidget* tracks_widget = this->getWidget<DynamicRibbonWidget>("tracks");
     assert( tracks_widget != NULL );
     
-    RibbonWidget* tabs = this->getWidget<RibbonWidget>("trackgroups");
-    assert( tabs != NULL );
-       
     // Reset GP list everytime (accounts for locking changes, etc.)
     gps_widget->clearItems();