mail/libspf2: Update to newer snapshot (d14abff)

• Bump PORTREVISION for package change

Changes: https://github.com/shevek/libspf2/commits/master
PR: 274215
Reported by: pi
Security: CVE-2023-42118

(cherry picked from commit e0ce4912961cb8fcb88ea096eef3c3f82752be0b)