Don't add "remove row" button if there is only one row

InvenTree/templates/js/translated/order.js

@@ -655,12 +655,14 @@ function receivePurchaseOrderItems(order_id, line_items, options={}) {
             );
         }
 
+        if (line_items.length > 1) {
             buttons += makeIconButton(
                 'fa-times icon-red',
                 'button-row-remove',
                 pk,
                 '{% trans "Remove row" %}',
             );
+        }
 
         buttons += '</div>';