Substitua isso:
include_once 'inc/php/config.php';
include_once 'inc/php/functions.php';
com
include_once dirname(__FILE__) . '/inc/php/config.php';
include_once dirname(__FILE__) . '/inc/php/functions.php';
include_once 'inc/php/config.php';
include_once 'inc/php/functions.php';
include_once dirname(__FILE__) . '/inc/php/config.php';
include_once dirname(__FILE__) . '/inc/php/functions.php';