Don't play 'menu click' sound for right clicks (Fixes #3919)

apps/openmw/mwinput/inputmanagerimp.cpp

@@ -710,7 +710,7 @@ namespace MWInput
             if (MyGUI::InputManager::getInstance ().getMouseFocusWidget () != 0)
             {
                 MyGUI::Button* b = MyGUI::InputManager::getInstance ().getMouseFocusWidget ()->castType<MyGUI::Button>(false);
-                if (b && b->getEnabled())
+                if (b && b->getEnabled() && id == SDL_BUTTON_LEFT)
                 {
                     MWBase::Environment::get().getSoundManager ()->playSound ("Menu Click", 1.f, 1.f);
                 }