bsd.own.mk changes break overriding FC

[Mark Davies <mark%ecs.vuw.ac.nz@localhost>]

To change the fortran compiler used in pkgsrc you add the following two 
lines to mk.conf

PKGSRC_FORTRAN= g95
FC= g95

since the May changes to bsd.own.mk this no longer works as the setting of 
FC in bsd.own.mk overrides the value set in mk.conf.  I've got it working 
by commenting out the setting in line 454 of bsd.own.mk but thats 
obviously not the way forward.

cheers
mark