Fix infra scenario repo server cluster

The container affinity was not set for the repo server ansible group
so only one was created, rather than 3.

To test repo server synchronisation we need 3 repo servers.

Change-Id: I3fdb94f707c9972b5ddb6d9f6fba4af92f3c4e3b

etc/openstack_deploy/openstack_user_config.yml.aio.j2

@@ -215,7 +215,6 @@ shared-infra_hosts:
       galera_container: 3
       memcached_container: 3
       rabbit_mq_container: 3
-      repo_container: 3
 {% endif %}
 
 repo-infra_hosts:
@@ -223,5 +222,9 @@ repo-infra_hosts:
 {% if bootstrap_host_install_method == 'distro' %}
     affinity:
       repo_container: 0
+{% endif %}
+{% if 'infra' in bootstrap_host_scenarios_expanded %}
+    affinity:
+      repo_container: 3
 {% endif %}
     ip: 172.29.236.100