[Exim] FreeBSD ports for Exim updated to 4.22

Hi folks,

The FreeBSD ports for Exim have been updated to 4.22.

Again, please note that non-ACL exiscan support has been removed. If
you're upgrading an installation that is configured to use the non-ACL
exiscan patch, you'll need to edit your configuration.

As a reminder, note that you can submit official wishlist patches for
inclusion under the WITH_WISHLIST flag. If there's a wishlist item that
you use, feel free to bring it to my attention and I'll include it.

The port currently has no wishlist items under WITH_WISHLIST; the only
one included previously has been incorporated into the Exim
distribution.

Ciao,
Sheldon.