Default server port is used instead of the management interface port in the guide about running Keycloak in a container

### Description

In the [Running Keycloak in a container](https://www.keycloak.org/server/containers#_starting_the_optimized_keycloak_container_image) guide, the default server port (i.e. 8443) is used instead of the management port (i.e. 9000) in health and metrics URLs.