Failed connect to github.com:443； Connection refused

git clone 报错：

[lj@localhost ~]$ git  clone  https://github.com/libra/libra.git &&cd  libra
正克隆到 'libra'...
fatal: unable to access 'https://github.com/libra/libra.git/': Failed connect to github.com:443; Connection refused

解决方法：
1.查找网站IP

2. 打开hosts文档并修改

sudo vim /etc/hosts

3.再次运行