biology/ncbi-blast+: Add MAKE_JOBS_UNSAFE
See PR 214997.
While the build was succeeding on the cluster, it was failing for me in a
11.0-RELEASE-p1 amd64 poudriere jail.
http://pkg.awarnach.mathstat.dal.ca/data/11amd64-default/2016-12-21_22h08m09s/logs/errors/ncbi-blast+-2.5.0.log
After adding MAKE_JOBS_UNSAFE=yes, the build in the same jail succeeded.
http://pkg.awarnach.mathstat.dal.ca/data/11amd64-default/2016-12-21_23h13m19s/logs/ncbi-blast+-2.5.0.log