youtube module loads preview picture in better quality now

app/modules/elementdispatcher.php

@@ -621,7 +621,7 @@ class ElementDispatcher {
                                $vid);
 
                 $thumbnail = sprintf("<div class=\"video-thumbnail\"><a href=\"%s\" data-featherlight=\"#%s\">"
-                                     ."<img class=\"thumbnail\" src=\"https://img.youtube.com/vi/%s/mqdefault.jpg\" alt=\"video-preview\"/>"
+                                     ."<img class=\"thumbnail\" src=\"https://img.youtube.com/vi/%s/maxresdefault.jpg\" alt=\"video-preview\"/>"
                                      ."<img class=\"play-button\" src=\"%s\" alt=\"play-button\" />"
                                      ."</a></div><div class=\"lightbox\" id=\"%s\" >%s</div>",
                                      "https://www.youtube.com/watch?v=".$vid,