Fix MD5 TCP signature usage with latest tcpmd5 kernel module

PR: 21890
Submitted by: ae
Reported by: Joseph Mulloy <freebsd-bugs@joe.mulloy.me>
Approved by: melifaro (maintainer)

Fix build with option FIREWALL

PR: 217150
Submitted by: olivier
Reported by: O. Hartmann <ohartmann@walstatt.org>
Approved by: melifaro (maintainer)
Sponsored by: Orange