okey but i think it was bug not feature 🙂
Solved
go to sliders.php
– find function removeslider($id)
– add following code in start of else part
$sql_remov_images=$wpdb->prepare("DELETE FROM ".$wpdb->prefix."huge_itslider_images WHERE slider_id = %d", $id);
$wpdb->query($sql_remov_images);