Remove direct call to add_new_user_to_blog() as this is already hooked into wpmu_activate_user.

The second argument passed by that hook is not $email, so let's change that. It is not used.

props wonderboymusic.
fixes #15173.



git-svn-id: https://core.svn.wordpress.org/trunk@23535 1a063a9b-81f0-0310-95a4-ce76da25c4cd