security/unix-selfauth-helper: Update to 1.1

Changes:
https://github.com/Zirias/unix-selfauth-helper/releases/tag/v1.1

Also remove the post-install script checking for FreeBSD versions with
unpatched pam_exec.so. 13.0 and 13.1 were affected, 13.0 is long since
EOL, 13.1 will be EOL in a few days and the issue was already fixed in
-p1.

Approved by: tcberner (mentor, implicit)