(Deploy previews) OAuth doesn't work

**Describe the bug**
Because the OAuth settings are set to specific whitelisted callback URLs, signing in on deploy previews is impossible currently.

Solution would be to pass the origin to the strategy meta option and redirect from production to the preview url after auth is successful.

**To Reproduce**
Steps to reproduce the behavior:
1. Go to deploy preview (not production)
2. Try to sign in with GitHub

**Expected behavior**
Be able to sign in with OAuth