syncrepo: let mirrorsync perform the repo syncing

This role will still handle setting up nginx and rsyncd, due to specific configuration requirements these services have.

We're also effectively relieving build.archlinux.org of rsyncd duties as it is not something it should be doing anyway.

roles/mailman/templates/mailman.cfg.j2

@@ -4,7 +4,7 @@ layout: fhs
 
 [database]
 class: mailman.database.postgresql.PostgreSQLDatabase
-url: postgres://{{ vault_mailman_db_user }}:{{ vault_mailman_db_password }}@/mailman
+url: postgresql://{{ vault_mailman_db_user }}:{{ vault_mailman_db_password }}@/mailman
 
 [webservice]
 admin_user: {{ vault_mailman_admin_user }}