fix(web): preserve canonical feed reader link href

Author: gildesmarais

public/feed-reader-link.js

@@ -1,6 +1,10 @@
 document.addEventListener('DOMContentLoaded', function () {
   var readerLink = document.querySelector('[data-feed-reader-link]');
   if (!readerLink) return;
+  var currentHref = readerLink.getAttribute('href');
+  if (currentHref && currentHref !== '#') return;
 
-  readerLink.setAttribute('href', 'feed:' + window.location.href);
+  var pageHref = window.location.href;
+  var feedHref = pageHref.indexOf('feed:') === 0 ? pageHref : 'feed:' + pageHref;
+  readerLink.setAttribute('href', feedHref);
 });