Avoiding animation for nested lists

This should avoid animations for `ui horizontal list` nested into `ui animated list` like this:

```html
<div class="ui animated list">
  <div class="item">Item 1</div>
  <div class="item">
    <div class="ui horizontal list">
      <div class="item">Item H1</div>
      <div class="item">Item H2</div>
    </div>
  </div>
  <div class="item">Jobs</div>
</div>
```

See [this jsfiddle](http://jsfiddle.net/hez1w32z/3/) for reproduction