image-serve: redirect root to /v2

Nobody needs to see the default apache page, let's just redirect to v2
so operators aren't confused.

Change-Id: I465bcf9358bf85dd8e7f4bd199b5dcee703b8ab4

roles/tripleo-image-serve/templates/image-serve.conf.j2

@@ -5,6 +5,7 @@ Listen {{ container_registry_port }}
     ServerSignature Off
     CustomLog "/var/log/httpd/image_serve_access.log" combined
     SetEnvIf X-Forwarded-Proto https HTTPS=1
+    RedirectMatch ^/$ /v2
 
     <Directory {{ image_data_dir }}>
         # This assumes a file exists containing {} at