message: camera: move callback resets into deinit
  As a general rule we should have all custom things in `init()`
  and `deinit()` instead of the constructor or destructor.
diff: @@ -23,26 +23,6 @@ CameraImpl::CameraImpl(System &system) : PluginImplBase(system)
  CameraImpl::~CameraImpl()
  {
  _parent->unregister_plugin(this);
  -
  - {
  - std::lock_guard<std::mutex> lock(_status.mutex);
  - _status.callback = nullptr;
  - }
  -
  - {
  - std::lock_guard<std::mutex> lock(_get_mode.mutex);
  - _get_mode.callback = nullptr;
  - }
  -
  - {
  - std::lock_guard<std::mutex> lock(_capture_info.mutex);
  - _capture_info.callback = nullptr;
  - }
  -
  - {
  - std::lock_guard<std::mutex> lock(_video_stream_info.mutex);
  - _video_stream_info.callback = nullptr;
  - }
  }
  void CameraImpl::init()
  @@ -91,6 +71,26 @@ void CameraImpl::deinit()
  {
  _parent->remove_call_every(_status.call_every_cookie);
  _parent->unregister_all_mavlink_message_handlers(this);
  +
  + {
  + std::lock_guard<std::mutex> lock(_status.mutex);
  + _status.callback = nullptr;
  + }
  +
  + {
  + std::lock_guard<std::mutex> lock(_get_mode.mutex);
  + _get_mode.callback = nullptr;
  + }
  +
  + {
  + std::lock_guard<std::mutex> lock(_capture_info.mutex);
  + _capture_info.callback = nullptr;
  + }
  +
  + {
  + std::lock_guard<std::mutex> lock(_video_stream_info.mutex);
  + _video_stream_info.callback = nullptr;
  + }
  }
  void CameraImpl::enable()
  