Use config_template as a collection

Since we still use ceph-ansible that has their own implementation of
config_template module it's worth to use mentioned module as a collection
explicitly.

Change-Id: I4c5c6a836b40805938735bc9c0d8d4d60d23ab61

meta/main.yml

@@ -40,4 +40,8 @@ galaxy_info:
     - tempest
     - development
     - openstack
+
+collections:
+  - openstack.config_template
+
 dependencies: []