SDL mouse wheel speed fix.

Default scroll speed wasn't delta-modified, so scroll gui controls were very slow when scrolled via mouse wheel.. This corrects the issue.

Engine/source/windowManager/sdl/sdlWindow.cpp

@@ -434,7 +434,7 @@ void PlatformWindowSDL::_triggerMouseLocationNotify(const SDL_Event& evt)
 
 void PlatformWindowSDL::_triggerMouseWheelNotify(const SDL_Event& evt)
 {
-   wheelEvent.trigger(getWindowId(), 0, evt.wheel.x, evt.wheel.y);
+   wheelEvent.trigger(getWindowId(), 0, evt.wheel.x, evt.wheel.y * WHEEL_DELTA);
 }
 
 void PlatformWindowSDL::_triggerMouseButtonNotify(const SDL_Event& event)