To keep using the same context-path with RH-SSO, my customer plan to deploy RHBK with `--http-relative-path=/auth` option.
But with this configuration, the request to the root path "https://<rhbk-domain>/" would be responded with "Resource not found" message and HTTP status code 404.
In the case of RH-SSO, it redirected the request to the "/auth", and the welcome page was shown.

Sometimes end-users send request to the root path, and the customer want to redirect to the appropriate page instead of displaying RESTEasy default 404 error page.

When the `http-relative-path` is set, after accessing the Keycloak base-url root path, the user/client should be redirected to the relative path.

For example:
After accessing `localhost:8080`, the page is redirected to `localhost:8080/auth`

This improves the UX and is requested by customers running with RH-SSO today and planning for migration to RHBK.

Same issue was reported in keycloak GitHub discussion - https://github.com/keycloak/keycloak/discussions/10274

See Also:
https://github.com/keycloak/keycloak/issues/32863
https://github.com/quarkusio/quarkus/issues/42840