message: build fix for Windows
diff: @@ -245,7 +245,7 @@ namespace ospray {
  const vec3i &index, const vec3i &count)
  {
  auto &volume = objectFromAPIHandle<Volume>(_volume);
  - volume.setRegion(source, index, count);
  + return volume.setRegion(source, index, count);
  }
  void MPIDistributedDevice::setString(OSPObject _object,
  