[systemd] Refusing to accept PID outside of service control group, acquired through unsafe symlink chain

在高版本上用systemd启动时, 会收到 `Refusing to accept PID outside of service control group, acquired through unsafe symlink chain` 错误, 因为systemd不允许启动的服务在cgroup之外. 启动脚本是不是可以优化一下?
```
[Unit]
Description=apollo config service
After=network.target

[Service]
Type=forking
Restart=on-failure
PIDFile=/apollo/configservice/apollo-configservice/apollo-configservice.pid
# RemainAfterExit=true
ExecStart=/apollo/configservice/scripts/startup.sh
ExecStop= /apollo/configservice/scripts/shutdown.sh
[Install]
WantedBy=multi-user.target

```