title: ansible ignore the run_once configuration on task
body: <p>I am using Ansible and I want to run a task only once. I follow the documentation about how to configure and <a href="http://docs.ansible.com/playbooks_delegation.html#run-once">run a task only once</a></p>
  
  <pre><code>- name: apt update
    shell: apt-get update
    run_once: true
  </code></pre>
  
  <p>But when I run Ansible, it always runs this task. How can I run my task only once.</p>