message: build fixes for offline app
diff: // ======================================================================== //
  #include "ospapp/OSPApp.h"
  -#include "common/sg/SceneGraph.h"
  #include "ospcommon/utility/SaveImage.h"
  -#include "sg/Renderer.h"
  -#include "sg/common/FrameBuffer.h"
  +#include "sg/SceneGraph.h"
  #ifdef OSPRAY_APPS_ENABLE_DENOISER
  #include <OpenImageDenoise/oidn.hpp>
  