Handling JWT expired

[gandalfb]

Thank you for this awesome work.
I am currently trying JWT Authorization and I just realized, that the FORWARD_TOKEN_HEADER_NAME=X-Forwarded-Jwt won't be updated if the JWT expires.

With Keycloak using Access Token Lifespan of 5 Minutes, it looks like to set the "Lifetime" of forward auth to <5 Minutes?

It looks like the JWT Expiration is not checked and jwt token updated within traefik-forward-auth?

I hope its a valid question and I did not miss a point in documentation.