ssh: connect to host Centos7.6 port 22: Connection refused lost connection
解决办法：
You can try the VPN or if you have been using it before, try to turn it off and connect it again.
SSH免密登录配置成功后不生效
authorized_keys不能对组有写权限，具体可参考https://blog.csdn.net/lisongjia123/article/details/78513244
