Fix WebHook and special symbols in credentials
Created by: dmedvinsky
When using web hook with credentials secured web resource, one needs to put the credentials in the hook URL.
If the credentials contain special symbols (e.g. @ or #), it should be URL-quoted (e.g. %40 instead of @).
But when Gitlab is making a request, it should unquote the symbols before base64-encoding them.
P.S. I'm not sure how to write tests for this, so if anyone can help me, it'd be much appreciated.