Update MallDemoApplication.java

mall-demo/src/main/java/com/macro/mall/MallDemoApplication.java → mall-demo/src/main/java/com/macro/mall/demo/MallDemoApplication.java

-package com.macro.mall;
+package com.macro.mall.demo;
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;