org\Upload::__set PHP Method

    public function __set($name, $value)
    {
        if (isset($this->config[$name])) {
            $this->config[$name] = $value;
            if ('driverConfig' == $name) {
                //改变驱动配置后重置上传驱动
                //注意：必须选改变驱动然后再改变驱动配置
                $this->setDriver();
            }
        }
    }