devel/gearmand: Mark BROKEN on FreeBSD 12+
Outdated and doesn't build on 12+
References:
https://portsfallout.com/fallout?port=devel%2Fgearmand$
PR: 255212
Reported by: daniel.engberg.lists@pyret.net
MFH: 2021Q2
(cherry picked from commit 143627392d41563295e20a41a23473f671b6135b)