Fix Authorization Grant Revoking

[denymz]

Fix the 500 error code thrown by /api/auth/revoke. docs: https://docs.github.com/en/rest/reference/apps#delete-an-app-authorization

[syropian]

Thank you! I was was just working on this in the new version and created a reminder for myself to fix it in this version too, but I guess you read my mind 😄