filter by item_notshown instead of obj_type

Zotlabs/Module/Ping.php

@@ -401,10 +401,9 @@ class Ping extends \Zotlabs\Web\Controller {
 				WHERE item_unseen = 1 and uid = %d
 				$item_normal
 				AND author_xchan != '%s'
-				AND obj_type != '%s'",
+				AND item_notshown = 0",
 				intval(local_channel()),
-				dbesc($ob_hash),
-				dbesc(ACTIVITY_OBJ_FILE)
+				dbesc($ob_hash)
 			);
 
 			if($r) {