Revert previous commit. It not broken for everyone. It looks like the configure
script is using sysctl kern.osreldate (ie. __FreeBSD_version) to detect the
presenxe of sigignore; this happens to fail on QAT and PointyHat (and for
anyone having the kernel version different that the installed herders version,
one before and the other after the addition of sigignore in HEAD or 8-STABLE).
Requested by: glewis@ (maintainer), Rob Farmer <email@example.com>