message: fix AIO_free crash when php request shutdown.
diff: @@ -394,6 +394,9 @@ static int swAioBase_read(int fd, void *inbuf, size_t size, off_t offset)
  void swAioBase_destroy()
  {
  swThreadPool_free(&swAioBase_thread_pool);
  + if (SwooleG.main_reactor)
  + {
  SwooleG.main_reactor->del(SwooleG.main_reactor, swAioBase_pipe_read);
  + }
  swoole_aio_pipe.close(&swoole_aio_pipe);
  }
  