Failed to connect to github.com port 443
电脑无法访问github，重启电脑、重启网络、开启FQ都无效，ping也ping不通
解决办法：
1. 打开https://github.com.ipaddress.com/ 如下图
2.打开https://fastly.net.ipaddress.com/github.global.ssl.fastly.net#ipinfo 如下图：
3.打开https://github.com.ipaddress.com/assets-cdn.github.com 如下图：
4.打开电脑的hosts文件，把上图中的地址写进host中，然后保存即可
140.82.113.3(图1的IP Address) github.com 199.232.69.194(图2的IP Address) github.global.ssl.fastly.net 185.199.108.153(图3的IP Address) assets-cdn.github.com 185.199.109.153(图3的IP Address) assets-cdn.github.com 185.199.110.153(图3的IP Address) assets-cdn.github.com 185.199.111.153(图3的IP Address) assets-cdn.github.com
5.在终端在输以下指令刷新DNS（需要权限）
sudo killall -HUP mDNSResponder;say DNS cache has been flushed