message: Fix Http2 Client null pointer
diff: @@ -1325,11 +1325,14 @@ static PHP_METHOD(swoole_http2_client_coro, recv)
  while (true)
  {
  + if (!h2c->is_available())
  + {
  + RETURN_FALSE;
  + }
  if (!h2c->recv_packet(timeout))
  {
  RETURN_FALSE;
  }
  -
  enum swReturn_code ret = h2c->parse_frame(return_value);
  if (ret == SW_CONTINUE)
  {
  