youtubechannel-block.html.twig in YoutubeChannel 8

{% if youtube_content is empty  %}
  <h3>Sorry, there are no videos available on this channel.</h3>
{% else %}
  <div id="youtubechannel-player" style="width:{{youtube_content.width}}px; height:{{youtube_content.height}}px;">
     <iframe id="youtubechannel-frame" title="Youtube Video Player" width="{{youtube_content.width}}px" height="{{youtube_content.height}}px;" src="" frameborder="0" allowfullscreen></iframe>  
  </div>
  <div id="youtubechannel-list" style="width: {{youtube_content.width}}px;">
    <ul>
    {% for i in youtube_content.content|keys %}
      <li><a href="#{{i}}"><img src="{{youtube_content.content[i]}}"></a></li>
    {% endfor %}
    </ul>
  </div> 
{% endif %}