今天要把代码提交到 GitHub 仓库时，无法提交。
显示以下报错：
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
SHA256:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.
Please contact your system administrator.
Add correct host key in /root/.ssh/known_hosts to get rid of this message.
Offending RSA key in /root/.ssh/known_hosts:1
Host key for github.com has changed and you have requested strict checking.
Host key verification failed.
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.
一开始我以为 GitHub 的 SSH keys 没有了，但是我去加的时候，提示我
Key is already in use。
后来通过搜索，我使用下面的方法解决了：
首先在命令行输入：ssh-keygen -R github.com
然后，在用 git push 提交代码的时候按他的提示来操作就可以了。
之后可以提交成功了。
