message: offboard: switch to user callback queue
diff: @@ -74,7 +74,8 @@ void OffboardImpl::start_async(Offboard::ResultCallback callback)
  if (_mode == Mode::NotActive) {
  if (callback) {
  - callback(Offboard::Result::NoSetpointSet);
  + _parent->call_user_callback(
  + [callback]() { callback(Offboard::Result::NoSetpointSet); });
  }
  return;
  }
  @@ -114,7 +115,7 @@ void OffboardImpl::receive_command_result(
  {
  Offboard::Result offboard_result = offboard_result_from_command_result(result);
  if (callback) {
  - callback(offboard_result);
  + _parent->call_user_callback([callback, offboard_result]() { callback(offboard_result); });
  }
  }
  