Improve fail message

Co-authored-by: Scott Davidson <[email protected]>

Author: sjpb

ansible/roles/passwords/tasks/validate.yml

@@ -1,4 +1,4 @@
 - name: Assert secrets created
   assert:
     that: (hostvars[inventory_hostname].keys() | select('contains', 'vault_') | length) > 1 # 1 as may have vault_testuser_password defined in dev
-    fail_msg: "No inventory variables 'vault_*' found: Has ansible/adhoc/generate-passwords.yml been run"
+    fail_msg: "No inventory variables 'vault_*' found: Has ansible/adhoc/generate-passwords.yml been run?"