Greenwave - removing hard-coded version

These got resolved:
 - fedora-infra/bodhi#2554
 - https://pagure.io/greenwave/issue/287

So we don't need anymore to specify the 0.9.4 version, but we can
just put it again to "prod".

roles/openshift-apps/greenwave/templates/imagestream.yml

@@ -20,9 +20,5 @@ spec:
       name: quay.io/factory2/greenwave:latest
 {% else %}
       # This is 'prod' tag is maintained by hand.
-      #name: quay.io/factory2/greenwave:prod
-      # But, pin it to 0.9.4 until we can resolve
-      # https://github.com/fedora-infra/bodhi/issues/2554
-      # https://pagure.io/greenwave/issue/287
-      name: quay.io/factory2/greenwave:0.9.4
+      name: quay.io/factory2/greenwave:prod
 {% endif %}