Error 500 on opening Profile page with "/" at the end

Steps to reproduce:

1. Open forum as anonym user
2. Go to user profile page via link like http://qa.jtalks.org/jcommune/user/
   note that there is "/" at the end of a link

Actual result Error 500 is shown (see exception in attachment)
Expected result Login page is opened

java.lang.UnsupportedOperationException: Username is not defined for anonymous user
	org.jtalks.jcommune.model.entity.AnonymousUser.getUsername(AnonymousUser.java:76)
	sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)