开源版21.7.8升级到最新21.7.9报错

禅道版本：开源版21.7.9，PHP 7.0，没有安装任何其他插件。

系统配置：centos7

开源版21.7.8升级到最新21.7.9

报错Fatal error: Class ztSessionHandler contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (SessionHandlerInterface::write) in/opt/zbox/app/zentao/framework/base/router.class.php on line3796