sunyu::update::fix bug about clearMonthCard info

shopping-cart-application-service/src/main/java/cn/freemud/service/impl/mcoffee/ShoppingCartMCoffeeServiceImpl.java

@@ -494,7 +494,7 @@ public class ShoppingCartMCoffeeServiceImpl {
         List<CartGoods> cartGoodsList = assortmentSdkService.getShoppingCart(partnerId, storeId, userId, sessionId, "", shoppingCartBaseService);
         for (CartGoods cartGoods : cartGoodsList) {
             if (StringUtils.equals(cartGoods.getCouponCode(),requestVo.getRedundancyCouponCode())){
-                cartGoods.setCouponCode("");
+                cartGoods.setCouponCode(null);
             }
 
             /**
@@ -2342,7 +2342,7 @@ public class ShoppingCartMCoffeeServiceImpl {
     private List<CartGoods> clearMonthCouponInfo(List<CartGoods> cartGoods,String couponCode){
         for (CartGoods cartGood : cartGoods) {
             if (StringUtils.equals(cartGood.getCouponCode(),couponCode)){
-                cartGood.setCouponCode("");
+                cartGood.setCouponCode(null);
             }
         }
         return cartGoods.stream().filter(t-> !StringUtils.equals("9999",t.getSkuId())).collect(Collectors.toList());