Make HAProxy only add the Authorization header if it is not present yet.
Make HAProxy only add the Authorization header if it is not present yet.

This allows passing OAuth bearer tokens to API endpoints via HAProxy.  The API
endpoints are not protected by HTTP basic auth, so we don't need the basic auth
credentials for these requests.

open-craft/opencraft,open-craft/opencraft,open-craft/opencraft,open-craft/opencraft,open-craft/opencraft