title: Disable close-on-click-modal in Element UI
body: <p>With (Vue) Element UI I'm trying to disable a Dialog element from closing on click.
  In the docs it say there is a close-on-click-modal attribute, but it's default is true and I have no idea on how to set it to false.</p>
  
  <p><code>close-on-click-modal="false"</code> gives this error: <code>"closeOnClickModal". Expected Boolean, got String.</code></p>
  
  <p>Is there a way to disable this setting?</p>