[Bug]: 500 (Internal Server Error) on invalid cookie

[Primexz]

OAuth2-Proxy Version

7.6.0

Provider

keycloak

Expected Behaviour

If I change the sessionstore (e.g. Cookie Storage to Redis) Storage, I expect that no Internal Server Error (500) is displayed for the user.
Changing the session store changes the layout of a cookie, which means that old cookies can no longer be parsed.

As a user, I expect the sign-in page of the OAuth2 proxy to be displayed by default instead of the error page.

Current Behaviour

If I currently change the session store as administrator, all users with an old cookie are currently shown an Internal Server Error (500).

If a user has a broken cookie (regardless of the value), an internal server error is currently displayed

Steps To Reproduce

1. login with the provider
2. manipulate the session cookie (enter something wrong, e.g. "foobar")
3. reload the page
4. an Internal Server Error should be displayed.

Possible Solutions

Forwarding to the OAuth2 provider if the cookie cannot be parsed.

Configuration details or additional information

No response