解决升级 Spring Boot 2.6后，因循环引用导致启动时报错的问题

Relying upon circular references is discouraged and they are prohibited by default. Update your application to remove the dependency cycle between beans. As a last resort, it may be possible to break the cycle automatically by setting spring.main. allow-circular-references to true. 

依赖循环引用是不鼓励的，默认情况下是禁止的。更新应用程序以删除bean之间的依赖循环。作为最后的手段，可以通过设置spring.main来自动打破循环。allow-circular-references为true。

可以通过在配置文件中配置如下属性以恢复正常

spring.main.allow-circular-references=true