message: mission: remove unused stuff
diff: @@ -73,7 +73,6 @@ public:
  private:
  void process_mission_current(const mavlink_message_t& message);
  void process_mission_item_reached(const mavlink_message_t& message);
  - void process_gimbal_information(const mavlink_message_t& message);
  void process_gimbal_manager_information(const mavlink_message_t& message);
  void receive_protocol_timeout();
  void wait_for_protocol();
  @@ -122,11 +121,6 @@ private:
  int last_current_mavlink_mission_item{-1};
  int last_reached_mavlink_mission_item{-1};
  std::vector<int> mavlink_mission_item_to_mission_item_indices{};
  - int num_mission_items_to_download{-1};
  - int next_mission_item_to_download{-1};
  - int last_mission_item_to_upload{-1};
  - Mission::ResultCallback result_callback{nullptr};
  - Mission::DownloadMissionCallback download_mission_callback{nullptr};
  Mission::MissionProgressCallback mission_progress_callback{nullptr};
  int last_current_reported_mission_item{-1};
  int last_total_reported_mission_item{-1};
  @@ -143,19 +137,6 @@ private:
  // Ultimate it needs a setter.
  bool _enable_absolute_gimbal_yaw_angle{true};
  - static constexpr unsigned MAX_RETRIES = 10;
  -
  - static constexpr uint8_t VEHICLE_MODE_FLAG_CUSTOM_MODE_ENABLED = 1;
  -
  - // FIXME: these chould potentially change anytime
  - // derived from:
  - // https://github.com/PX4/Firmware/blob/master/src/modules/commander/px4_custom_mode.h
  - static constexpr uint8_t PX4_CUSTOM_MAIN_MODE_AUTO = 4;
  - static constexpr uint8_t PX4_CUSTOM_SUB_MODE_AUTO_LOITER = 3;
  - static constexpr uint8_t PX4_CUSTOM_SUB_MODE_AUTO_MISSION = 4;
  -
  - static constexpr double RETRY_TIMEOUT_S = 0.250;
  -
  void* _gimbal_protocol_cookie{nullptr};
  enum class GimbalProtocol { Unknown, V1, V2 };
  std::atomic<GimbalProtocol> _gimbal_protocol{GimbalProtocol::Unknown};
  