PropertiesPropertySource类名写错了

[TARFighting]

这个位置的类名应该为PropertiesPropertySource
https://github.com/xuchengsheng/spring-reading/blob/master/spring-env/spring-env-propertySource/README.md#%E5%85%AD%E4%B8%BB%E8%A6%81%E5%AE%9E%E7%8E%B0