message: update mt_co.cc
diff: @@ -14,7 +14,6 @@ struct co_param
  int port;
  };
  -
  const int THREAD_N = 4;
  void co_thread(int i)
  @@ -39,6 +38,10 @@ void co_thread(int i)
  Socket *conn = sock.accept();
  if (!conn)
  {
  + if (sock.errCode == ECANCELED)
  + {
  + break;
  + }
  System::sleep(1);
  printf("accept error, errno=%d\n", sock.errCode);
  continue;
  