order feeds selected for update randomly

include/rssfuncs.php

@@ -117,7 +117,7 @@
 				AND ttrss_user_prefs.pref_name = 'DEFAULT_UPDATE_INTERVAL'
 				$login_thresh_qpart $update_limit_qpart
 				$updstart_thresh_qpart
-			ORDER BY feed_url $query_limit");
+			ORDER BY $random_qpart $query_limit");
 
 		$user_prefs_cache = array();