在nutzbook中，关于shiro集成那块，在“新增UserService”这一节，写到“这里用到了sha256加盐算法,将对应shiro.ini中配置”，但是后面shiro.ini并没有什么加密配置

[main]
nutzdao_realm = net.wendal.nutzbook.shiro.realm.SimpleAuthorizingRealm

authc = org.nutz.integration.shiro.SimpleAuthenticationFilter
authc.loginUrl  = /user/login
logout.redirectUrl= /user/login

[urls]
/rs/*        = anon
/user/logout = logout
/user/error  = anon
/user/login  = anon
/user/profile/active/mail = anon

why？