Thanks for flagging this up and sorry about that. For context, there’s been a recent wave of spam on code.djangoproject.com and we’ve been tweaking the antispam rules to try to fight that.
Seems like we tightened the rules a bit too much, GitHub should definitely be allowed.
I just wanted to mention that thanks to your report we were able to track down and fix the issue. It should now be possible to post links to github again without being marked as spam
If you experience any other bugs or inconveniences then please don’t hesitate to report them, either here on the forum, or by filing an issue on Issues · django/code.djangoproject.com · GitHub