message: added client_coro::$connected property.
diff: @@ -226,6 +226,7 @@ void swoole_client_coro_init(int module_number TSRMLS_DC)
  zend_declare_property_long(swoole_client_coro_class_entry_ptr, SW_STRL("sock")-1, 0, ZEND_ACC_PUBLIC TSRMLS_CC);
  zend_declare_property_long(swoole_client_coro_class_entry_ptr, ZEND_STRL("type"), 0, ZEND_ACC_PUBLIC TSRMLS_CC);
  zend_declare_property_null(swoole_client_coro_class_entry_ptr, ZEND_STRL("setting"), ZEND_ACC_PUBLIC TSRMLS_CC);
  + zend_declare_property_bool(swoole_client_coro_class_entry_ptr, ZEND_STRL("connected"), 0, ZEND_ACC_PUBLIC TSRMLS_CC);
  zend_declare_class_constant_long(swoole_client_coro_class_entry_ptr, ZEND_STRL("MSG_OOB"), MSG_OOB TSRMLS_CC);
  zend_declare_class_constant_long(swoole_client_coro_class_entry_ptr, ZEND_STRL("MSG_PEEK"), MSG_PEEK TSRMLS_CC);
  @@ -334,6 +335,7 @@ static void client_onConnect(swClient *cli)
  {
  SWOOLE_GET_TSRMLS;
  zval *zobject = cli->object;
  + zend_update_property_bool(swoole_client_coro_class_entry_ptr, zobject, ZEND_STRL("connected"), 1 TSRMLS_CC);
  #ifdef SW_USE_OPENSSL
  if (cli->ssl_wait_handshake)
  {
  @@ -355,6 +357,7 @@ static void client_onClose(swClient *cli)
  return;
  }
  php_swoole_client_free(zobject, cli TSRMLS_CC);
  + zend_update_property_bool(swoole_client_coro_class_entry_ptr, zobject, ZEND_STRL("connected"), 0 TSRMLS_CC);
  client_execute_callback(zobject, SW_CLIENT_CB_onClose);
  #if PHP_MAJOR_VERSION < 7
  sw_zval_ptr_dtor(&zobject);
  @@ -973,6 +976,7 @@ static PHP_METHOD(swoole_client_coro, close)
  swoole_client_coro_property *ccp = swoole_get_property(getThis(), 1);
  ccp->iowait = SW_CLIENT_CORO_STATUS_CLOSED;
  cli->released = 1;
  + zend_update_property_bool(swoole_client_coro_class_entry_ptr, getThis(), ZEND_STRL("connected"), 0 TSRMLS_CC);
  php_swoole_client_free(getThis(), cli TSRMLS_CC);
  RETURN_TRUE;
  