Be consistent about if :5000 is included in the registrry variable or not

[erikmartino]

I would much prefer the k8s101.md version. So you can easily use an external registry.

k8s101.md:$ export registry="$(kubectl get svc/registry -ojsonpath='{.spec.clusterIP}'):5000"
k8sprod.md:$ export registry=$(kubectl get svc/registry -ojsonpath="{.spec.clusterIP}")