fix: fix return value of janus-idp.hostname

[Zaperex]

Description of the change

Fixed the helm chart's helper template so that the janus-idp.hostname returns the correct value that matches the route host when the clusterRouterBase is defined.

Existing or Associated Issue(s)

Fixes #97

Additional Information

Checklist

• Chart version bumped in Chart.yaml according to semver.
• Variables are documented in the values.yaml and added to the README.md. The pre-commit utility can be used to generate the necessary content. Use pre-commit run -a to apply changes.
• JSON Schema template updated and re-generated the raw schema via pre-commit hook.
• List tests pass for Chart using the Chart Testing tool and the ct lint command.

[Zaperex]

I think the CI tests are failing since the helm chart is currently pulling the quay.io/janus-idp/backstage-showcase:latest which currently doesn't work with the default configurations.

This is most likely by the test-connection pod is unable to get a response from the backstage deployment pod since the pod has already stopped due to the backend failing to start up.

[Zaperex]

I ran the ct install --config ct-install.yaml test locally on Openshift Local after changing the image in the values.yaml to quay.io/janus-idp/backstage-showcase:nightly-20230929 and it passed.

[kadel]

@Zaperex If you rebase with the current main branch, it should fix the testing issue.

[tumido]

/lgtm
/approve