message: Do not report -1 as a current mission item
diff: @@ -810,6 +810,11 @@ void MissionImpl::report_progress()
  int current = current_mission_item();
  int total = total_mission_items();
  + // Do not report -1 as a current mission item
  + if (current == -1) {
  + return;
  + }
  +
  bool should_report = false;
  {
  std::lock_guard<std::recursive_mutex> lock(_mission_data.mutex);
  