message: device_impl: fixed logic error in heartbeat timeout
diff: @@ -231,6 +231,10 @@ void DeviceImpl::check_heartbeat_timeout(DeviceImpl *self)
  if (elapsed_since_s(self->_last_heartbeat_received_time) > DeviceImpl::_HEARTBEAT_TIMEOUT_S) {
  if (self->_heartbeats_arriving) {
  self->_parent->notify_on_timeout(self->_target_uuid);
  + self->_heartbeats_arriving = false;
  + }
  + } else {
  + if (!self->_heartbeats_arriving) {
  self->_heartbeats_arriving = true;
  }
  }
  