Traefik handles auth forwarding but does not manage redirections like Nginx.
Therefore, Authelia must redirect the user and Traefik will forward this
request.
To support both Nginx and Traefik, /api/verify is now configurable with the
'redirect' get parameter. If the verification fails and 'redirect' is not
provided the response will be a 401 error as before.
If the parameter is provided and set to any URL, the response will be a
redirection (302) to this URL.
Clement Michaud