message: gltf_viewer: fix ColorGrading leak.
diff: @@ -775,6 +775,7 @@ int main(int argc, char** argv) {
  engine->destroy(app.scene.groundVertexBuffer);
  engine->destroy(app.scene.groundIndexBuffer);
  engine->destroy(app.scene.groundMaterial);
  + engine->destroy(app.colorGrading);
  delete app.viewer;
  delete app.materials;
  