message: Memory security optimization
diff: @@ -135,7 +135,7 @@ void swoole_client_coro_init(int module_number)
  zend_declare_property_long(swoole_client_coro_ce, ZEND_STRL("errCode"), 0, ZEND_ACC_PUBLIC);
  zend_declare_property_string(swoole_client_coro_ce, ZEND_STRL("errMsg"), "", ZEND_ACC_PUBLIC);
  zend_declare_property_long(swoole_client_coro_ce, ZEND_STRL("fd"), -1, ZEND_ACC_PUBLIC);
  - zend_declare_property_null(swoole_client_coro_ce, ZEND_STRL("socket"), ZEND_ACC_PUBLIC);
  + zend_declare_property_null(swoole_client_coro_ce, ZEND_STRL("socket"), ZEND_ACC_PRIVATE);
  zend_declare_property_long(swoole_client_coro_ce, ZEND_STRL("type"), 0, ZEND_ACC_PUBLIC);
  zend_declare_property_null(swoole_client_coro_ce, ZEND_STRL("setting"), ZEND_ACC_PUBLIC);
  zend_declare_property_bool(swoole_client_coro_ce, ZEND_STRL("connected"), 0, ZEND_ACC_PUBLIC);
  