I had a bug reported to me that I was able to reproduce. When authorizing to my Badges webapp, we get the following error:

error: invalid_request
error description: OAuth request must be over HTTPS

However, I checked and the request URL is:

https://stackexchange.com/oauth/dialog?client_id=74&redirect_uri=http://agent86ix.github.io/stackapps/badge/

...which appears to be using https:// as required.

I haven't touched the app in months, so unless something has changed and I'm oblivious, I'm not sure how it could be my bug. Could someone take a look and give some guidance?