WordPress安装Redis Object Cache后，修改/wp-content/object-cache.php，增加密码password参数，结果立即报一下错误：
Service Unavailable
The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later.
使用的是centos8操作系统+php8+php-fpm+redis5.2+mysql5.7环境，通过重启php-fpm即可解决：
#systemctl restart php-fpm