fix(客户管理)： 添加客户未选父级报错

smart-city-platform/src/main/java/com/bz/smart_city/service/impl/CustomerServiceImpl.java

@@ -230,7 +230,7 @@ public class CustomerServiceImpl implements CustomerService {
 
     // 更新父级客户的子客户数量
     protected void updateParentChildrenNum(Integer parentId) {
-        if(parentId > 0) {
+        if(parentId != null && parentId > 0) {
             Integer count = customerMapper.countChildrenNum(parentId);
             Customer customer = this.findById(parentId);
             customer.setId(parentId);