message: mission: copy callback before queueing it
  This way we make sure the callback object does not go out of scope
  before it gets called.
diff: @@ -1132,18 +1132,21 @@ void MissionImpl::copy_mission_item_vector(
  void MissionImpl::report_mission_result(const Mission::result_callback_t &callback,
  Mission::Result result)
  {
  - if (callback == nullptr) {
  + const auto temp_callback = callback;
  +
  + if (temp_callback == nullptr) {
  LogWarn() << "Callback is not set";
  return;
  }
  - _parent->call_user_callback([callback, result]() { callback(result); });
  + _parent->call_user_callback([temp_callback, result]() { temp_callback(result); });
  }
  void MissionImpl::report_mission_items_and_result(
  const Mission::mission_items_and_result_callback_t &callback, Mission::Result result)
  {
  - if (callback == nullptr) {
  + const auto temp_callback = callback;
  + if (temp_callback == nullptr) {
  LogWarn() << "Callback is not set";
  return;
  }
  @@ -1153,15 +1156,16 @@ void MissionImpl::report_mission_items_and_result(
  // Don't return garbage, better clear it.
  _mission_data.mission_items.clear();
  }
  - _parent->call_user_callback([callback, result, this]() {
  + _parent->call_user_callback([temp_callback, result, this]() {
  // This one is tricky because we keep the lock of the mission data during the callback.
  - callback(result, _mission_data.mission_items);
  + temp_callback(result, _mission_data.mission_items);
  });
  }
  void MissionImpl::report_progress()
  {
  - if (_mission_data.progress_callback == nullptr) {
  + const auto temp_callback = _mission_data.progress_callback;
  + if (temp_callback == nullptr) {
  return;
  }
  @@ -1183,7 +1187,6 @@ void MissionImpl::report_progress()
  if (should_report) {
  std::lock_guard<std::recursive_mutex> lock(_mission_data.mutex);
  - auto temp_callback = _mission_data.progress_callback;
  _parent->call_user_callback([temp_callback, current, total]() {
  LogDebug() << "current: " << current << ", total: " << total;
  temp_callback(current, total);
  