Fixes key-up propagation bug in menu system

git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/branches/irrlicht@3890 178a84e3-b1eb-0310-8ba1-8eac791a3b58

src/input/input_manager.cpp

@@ -475,6 +475,7 @@ bool InputManager::input(const SEvent& event)
         else
         {
             input(Input::IT_KEYBOARD, 0, key, 0, 0, programaticallyGenerated);
+            return true; // Don't propagate key up events
         }
     }
 #if 0 // in case we ever use mouse in-game...