Update un-yank icon as well

Author: di

warehouse/templates/manage/releases.html

@@ -71,7 +71,7 @@
               {% set confirm_name = "unyank_release" %}
               {% set slug = confirm_name + '-modal-{}'.format(loop.index) %}
               <a href="#{{ slug }}" class="dropdown__link">
-                <i class="fa fa-folder-plus" aria-hidden="true"></i>
+                <i class="fa fa-long-arrow-alt-right" aria-hidden="true"></i>
                 {% trans %}Un-yank{% endtrans %}
               </a>
             </li>