message: Change blueprint reference to blueprint class reference.
  This solves a weird popup warning that appears when starting the packaged demo.
diff: /*static*/ UClass* ACesiumCreditSystem::CesiumCreditSystemBP = nullptr;
  UCesiumCreditSystemBPLoader::UCesiumCreditSystemBPLoader() {
  - ConstructorHelpers::FObjectFinder<UBlueprint> blueprint(TEXT("Blueprint'/Cesium/CesiumCreditSystemBP.CesiumCreditSystemBP'"));
  - ACesiumCreditSystem::CesiumCreditSystemBP = blueprint.Object ? (UClass*) blueprint.Object->GeneratedClass : nullptr;
  + ConstructorHelpers::FObjectFinder<UClass> blueprintClassReference(TEXT("Class'/Cesium/CesiumCreditSystemBP.CesiumCreditSystemBP_C'"));
  + ACesiumCreditSystem::CesiumCreditSystemBP = (UClass*) blueprintClassReference.Object;
  }
  /*static*/ ACesiumCreditSystem* ACesiumCreditSystem::GetDefaultForActor(AActor* Actor) {
  