I was not aware of it, probably it is a new feature of the JanRain RPX product where they are adding more social features, there may be settings you can configure in the account settings at JanRain.
My guess is that even though it asks, it is ok to say no and it should still let you login. We aren't using or capturing that data nor requesting it as far as I know.
From what I can see in my account at JanRain, I'm not even able to enable requesting contact information because I'm not on the Pro Plan, so possibly it is a bug in RPX. It looks like it is disabled.
I'll look into this further with JanRain when I get a chance.