Followup comment fix from alt_demo user creation

Tweak a code comment based on a review comment from Steve Martinelli in
https://review.openstack.org/#/c/275121/ where the alt_demo user is now
always created.

Change-Id: I9e9a769f601e52c030e9f6953f1746788c24a185
diff --git a/lib/keystone b/lib/keystone
index 507ee55..6bad6b9 100644
--- a/lib/keystone
+++ b/lib/keystone
@@ -331,10 +331,10 @@
 # alt_demo             alt_demo   Member, anotherrole
 # invisible_to_admin   demo       Member
 
-# Group                Users      Roles                 Tenant
+# Group                Users            Roles                 Tenant
 # ------------------------------------------------------------------
-# admins               admin      admin                 admin
-# nonadmins            demo       Member, anotherrole   demo
+# admins               admin            admin                 admin
+# nonadmins            demo, alt_demo   Member, anotherrole   demo, alt_demo
 
 
 # Migrated from keystone_data.sh