Update to Drupal 8.0.0 beta 14. For more information, see https://drupal.org/node/2544542

core/themes/classy/templates/misc/feed-icon.html.twig

@@ -1,16 +0,0 @@
-{#
-/**
- * @file
- * Theme override for a feed icon.
- *
- * Available variables:
- * - url: An internal system path or a fully qualified external URL of the feed.
- * - icon: The rendered HTML (<img> tag) for the feed icon image.
- * - attributes: Remaining HTML attributes for the feed link.
- *   - title: A descriptive title of the feed link.
- *   - class: HTML classes to be applied to the feed link.
- *
- * @see template_preprocess_feed_icon()
- */
-#}
-<a href="{{ url }}"{{ attributes.addClass('feed-icon')|without('href') }}>{{ icon }}</a>