Update link to Hypercorn project

[damascene]

Hypercorn project seems to be using Github now

https://github.com/pgjones/hypercorn

Link to Gitlab is 404:
https://gitlab.com/pgjones/hypercorn

I've updated the link

Summary

Checklist

• [x ] I understand that this PR may be closed in case there was no previous discussion. (This doesn't apply to typos!)
• I've added a test for each change that was introduced, and I tried as much as possible to make a single atomic change.
• I've updated the documentation accordingly.

[Kludex]

Yep, thanks!