Fix typo in lib/keystone

nonadmin => nonadmins

Change-Id: I9d51e079c10f7c48b962a1d6f4577e8a6ec4a229
diff --git a/lib/keystone b/lib/keystone
index e2448c9..6520fc6 100644
--- a/lib/keystone
+++ b/lib/keystone
@@ -353,7 +353,7 @@
 # Group                Users      Roles                 Tenant
 # ------------------------------------------------------------------
 # admins               admin      admin                 admin
-# nonadmin             demo       Member, anotherrole   demo
+# nonadmins            demo       Member, anotherrole   demo
 
 
 # Migrated from keystone_data.sh