#569318 by Benjamin Melançon: Fixed hook_comment_load() never gets called.

modules/comment/comment.module

@@ -1511,6 +1511,7 @@ protected function attachLoad(&$comments) {
       $comment->node_type = 'comment_node_' . $comment->node_type;
       $comments[$key] = $comment;
     }
+    parent::attachLoad($comments);
   }
 }