Simply button to mark as out of stock

We had before the update (from 1.3.8 to 1.3.9h) of our site a simple button in admin to mark as products out of stock as we do not use stock levels so to make it easier for staff to update items as in stock we changed the code of admin/includes/modules/category_product_listing.php

at lines 332-333 we replaced it with

<td class="dataTableContent" align="right">
<?php                    
if ($products->fields['products_quantity'] <= 0 ) {
    echo '<a href="' . zen_href_link(FILENAME_CATEGORIES, 'action=setquantity&product_quantity=1&pID=' . $products->fields['products_id'] . '&cPath=' . $cPath . (isset($_GET['page']) ? '&page=' . $_GET['page'] : '')) . '">' . zen_image(DIR_WS_IMAGES . 'icon_red_on.gif', "Put a product back in stock") . '</a>';
} else {
    echo '<a href="' . zen_href_link(FILENAME_CATEGORIES, 'action=setquantity&product_quantity=0&pID=' . $products->fields['products_id'] . '&cPath=' . $cPath . (isset($_GET['page']) ? '&page=' . $_GET['page'] : '')) . '">' . zen_image(DIR_WS_IMAGES . 'icon_green_on.gif', "Mark a product out of stock") . '</a>';
}
?>

                <?php echo $products->fields['products_quantity']; ?>
                </td>
                <td class="dataTableContent" width="50" align="center">
```But now when clicking the button for product quantity it does not change it 

Has there been a security update that makes this not work anymore or is there any errors in the coding

Fixed it as missed out the customization on categories for the command setquantity