message: NO-TICKET: Logging erroneous synchronizer starts
diff: @@ -305,11 +305,19 @@ where
  match event {
  Event::Start(init_peer) => {
  match self.state {
  - State::None | State::Done | State::SyncingDescendants { .. } => {
  + State::None => {
  // No syncing configured.
  trace!("received `Start` event when in {} state.", self.state);
  Effects::new()
  }
  + State::Done | State::SyncingDescendants { .. } => {
  + // Illegal states for syncing start.
  + error!(
  + "should not have received `Start` event when in {} state.",
  + self.state
  + );
  + Effects::new()
  + }
  State::SyncingTrustedHash { trusted_hash, .. } => {
  trace!(?trusted_hash, "start synchronization");
  // Start synchronization.
  