Remove Google contact field

I am trying to remove the “Google+ Number” field from the contact info because it is autofilling and also autofilling one of the password fields, which means that users have to put in their password every time (or know to delete it).

I am using this code, and it works for all other fields, but not ‘gplus’ HELP!

function contactmethods( $contactmethods ) {
  unset($contactmethods['aim']);
  unset($contactmethods['jabber']);
  unset($contactmethods['yim']);
  unset($contactmethods['gplus']);
  return $contactmethods;
}
add_filter('user_contactmethods','contactmethods');