去掉SSH KEY密码

1. 使用openssl命令去掉私钥的密码
   openssl rsa -in ~/.ssh/id_rsa -out ~/.ssh/id_rsa_new
2. 备份旧私钥
   mv ~/.ssh/id_rsa ~/.ssh/id_rsa.backup
3. 使用新私钥
   mv ~/.ssh/id_rsa_new ~/.ssh/id_rsa
4. 设置权限
   chmod 600 ~/.ssh/id_rsa