message: camera: start sequence at 1
  This is according to the MAVLink spec.
diff: @@ -81,7 +81,7 @@ private:
  struct {
  std::mutex mutex {};
  - int sequence = 0; // TODO: maybe we need to start with 1, pending mavlink specs
  + int sequence = 1; // The MAVLink spec says the sequence starts at 1.
  } _capture;
  struct {
  