Traefik forwardauth middleware "silently" fails if `wb-auth` server is down / not reachable

[YuryHrytsuk]

This happens when traefik cannot reach wb-auth (let's say docker swarm dns failed to update records)

Affected components:

• all traefik routes using this middleware

Problem:

• it is not easy to identify this situation as no logs are point to the root problem (until traefik is on debug level). All affected routes return 500 with no hints what is going on

Read more: traefik/traefik#12234