Fix lazy loading images with discussion infinite scroll

src/www/js/_discussions.js

@@ -34,6 +34,9 @@ $(function() {
 
             $('.discussion-list-threads:not(.discussion-list-threads--sticky)').append(data);
 
+            // Load in lazy images
+            document.dtw.lazy();
+
             loading = false;
         }).always(function() {
             $('.pagination .loader').addClass('hide');