remove admin user from enrolling in demo course

playbooks/roles/demo/tasks/deploy.yml

@@ -50,7 +50,7 @@
     chdir: "{{ demo_edxapp_code_dir }}"
   become_user: "{{ common_web_user }}"
   with_items:
-      - "{{ demo_test_admin_and_staff_users }}"
+      - "{{ demo_test_and_staff_users }}"
   when: demo_checkout.changed
 
 - name: add test users to the certificate whitelist