message: Set promise value after stopping the land_async callback
diff: @@ -230,7 +230,8 @@ void usage(std::string bin_name)
  << "For example, to connect to the simulator use URL: udp://:14540" << std::endl;
  }
  -Telemetry::landed_state_callback_t landed_state_callback(std::shared_ptr<Telemetry>& telemetry, std::promise<void>& landed_promise)
  +Telemetry::landed_state_callback_t
  +landed_state_callback(std::shared_ptr<Telemetry>& telemetry, std::promise<void>& landed_promise)
  {
  return [&landed_promise, &telemetry](Telemetry::LandedState landed) {
  switch (landed) {
  @@ -245,8 +246,8 @@ Telemetry::landed_state_callback_t landed_state_callback(std::shared_ptr<Telemet
  break;
  case Telemetry::LandedState::IN_AIR:
  std::cout << "Taking off has finished." << std::endl;
  - landed_promise.set_value_at_thread_exit();
  telemetry->landed_state_async(nullptr);
  + landed_promise.set_value();
  break;
  case Telemetry::LandedState::UNKNOWN:
  std::cout << "Unknown landed state." << std::endl;
  