net/fort: Update to 1.6.4

• Update to 1.6.4
• Changelog: https://github.com/NICMx/FORT-validator/releases/tag/1.6.4

Approved by: Toni Kalombo <toni@devboks.com> (maintainer, implicit)
MFH: 2024Q4
Security: CVE-2024-48943

(cherry picked from commit 04db0aa821e38f8ec6ddbeadbe65af7cee9ec1ff)