в AdminProductsController
$this->fields_list['image'] = array(
'title' => $this->l('Image'),
'align' => 'center',
'image' => 'p',
'orderby' => false,
'filter' => false,
'search' => false
);
меняете на
$this->fields_list['id_image'] = array(
'title' => $this->l('Image'),
'align' => 'center',
'image' => 'p',
'orderby' => true,
'filter' => false,
'search' => false
);
либо делаете оверрайд контроллера