message: [dbus] unpublish mDNS services when leaving network
diff: @@ -1640,6 +1640,7 @@ void DBusThreadObject::LeaveNetworkHandler(DBusRequest &aRequest)
  mNcp->GetThreadHelper()->DetachGracefully([aRequest, this](otError error) mutable {
  SuccessOrExit(error);
  + mPublisher->Stop();
  SuccessOrExit(error = otInstanceErasePersistentInfo(mNcp->GetThreadHelper()->GetInstance()));
  exit:
  