Use Django messages in SocialAuthExceptionMiddleware even for anonymous users

[GregoryAveryWeir]

Django's messages framework works for authenticated or unauthenticated users, so I propose removing the check in SocialAuthExceptionMiddleware that only uses messages for authenticated users.

[omab]

Do you happen to know since when it works?

[GregoryAveryWeir]

I have not tested it, but the 1.2 docs say that the messages framework is a new feature "for both anonymous and authenticated clients:" https://docs.djangoproject.com/en/1.2/ref/contrib/messages/

It definitely works in 1.6.

[omab]

I've updated the code to use messages app by default. Thanks!