[Feature] 新增配置软件代理的功能

[Gentlesprite]

Checklist

• [x] I have already read docs/Tips.md, but my feature is not implemented.
• [x] My suggested feature was not mentioned by others, and it is not a duplicate feature.

Summary

在软件更新的时候，能否新增一个配置软件代理的功能，（如果不开TUN模式的话）直接裸连github这导致更新很慢。

Solution or Design

如题

[IiHuTao]

与#1317 重复？