[A端][修复]:作废券时候的异常问题

mallinkService/src/main/java/com/iformall/service/impl/WxCouponServiceImpl.java

@@ -138,7 +138,7 @@ public class WxCouponServiceImpl implements WxCouponService {
             wxCouponMapper.insertSelective(record);
 
         } else {
-            if (!record.getMerchantParams().isEmpty()) {
+            if (record.getMerchantParams() != null) {
                 List<JSONObject> merchantParamList = JSONObject.parseArray(record.getMerchantParams(), JSONObject.class);
 
                 WxCouponMerchant cmParam = new WxCouponMerchant();