修复{extension_two}字段下单时，老数据null导致的异常

app/common/repositories/store/order/StoreOrderRepository.php

@@ -745,7 +745,7 @@ class StoreOrderRepository extends BaseRepository
                     'order_type' => 0,
                     'extension_one' => round($total_extension_one, 2),
 //                    'extension_two' => $total_extension_two,
-                    'extension_two' => $product_attr_unique_datas['extension_two'],//@todo 此字段已被用于分佣比例
+                    'extension_two' => !empty($product_attr_unique_datas['extension_two'])?$product_attr_unique_datas['extension_two']:0.00,//@todo 此字段已被用于分佣比例
                     'orderInfo' => $cartInfo['order'],
                     'cartInfo' => $cartInfo['list'],
                     'order_sn' => $this->getNewOrderId() . ($k + 1),