Ubuntu 18.04 完全重装 SSH 服务
sudo apt-get remove openssh-server openssh-client --purge -y
sudo apt-get autoremove
sudo apt-get autoclean
sudo apt-get update
sudo apt-get install openssh-server openssh-client
sudo apt-get remove openssh-server openssh-client --purge -y
sudo apt-get autoremove
sudo apt-get autoclean
sudo apt-get update
sudo apt-get install openssh-server openssh-client