Org.keycloak/keycloak-quarkus-server: unable to restrict access to the admin console

A flaw was found in Keycloak. The Keycloak guides recommend to not expose /admin path to the outside in case the installation is using a proxy. The issue occurs at least via ha-proxy, as it can be tricked to using relative/non-normalized paths to access the /admin application path relative to /realms which is expected to be exposed.