Bug 32066: Check 2FA pref in check_cookie_auth

Bug 32066: Check 2FA pref in check_cookie_auth

Test plan:

Without this patch:
1. Set the syspref TwoFactorAuthentication (enforce or enabled)
2. Configure 2FA for a patron
3. Logout
4. Authenticate but don't enter the 2FA code
5. Switch off the syspref (disabled) [via another browser or so]
6. Patron is stuck on the [original] login screen. [Only removing
   the session cookie would resolve it.]

With this patch:
1. Follow the steps above again. But note that you can refresh
   your browser window to get in now.
2. Verify that Auth.t passes now too.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>