Automatically verify the setup account's email address

Summary: Although the defaults don't require a verified email address, it's easy to lock yourself out by accident by configuring `auth.require-email-verification` or `auth.email-domains` before setting up email. Just force-verify the initial/setup account's address.

Test Plan: Went through setup on a fresh install, saw address verify.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D8365