No need to explicitely include relation.lib its anyway included in common.inc

tbl_tracking.php

@@ -15,9 +15,6 @@ $url_query .= '&goto=tbl_tracking.php&back=tbl_tracking.php';
 $url_params['goto'] = 'tbl_tracking.php';;
 $url_params['back'] = 'tbl_tracking.php';
 
-// Get relation settings
-require_once './libraries/relation.lib.php';
-
 // Init vars for tracking report
 if (isset($_REQUEST['report']) || isset($_REQUEST['report_export'])) {
     $data = PMA_Tracker::getTrackedData($_REQUEST['db'], $_REQUEST['table'], $_REQUEST['version']);