warning: LF will be replaced by CRLF in app.iml.
The file will have its original line endings in your working directory.
解决方法
取消Git的自动替换 换行方式：
git config --global core.autocrlf flase
fatal: remote origin already exists.
先
git remote rm origin
然后
git remote add origin git@github.com:you name/xxx.git
