ports/170617: [maintainer update] Update net-mgmt/irrtoolset to 5.0.1

[Kevin Oberman]

I ran a full set of builds on redports and it all worked except on
10/i386 where it failed to build (actually package) libtool, so never
tried irrtoolset. :-(
-- 
R. Kevin Oberman, Network Engineer Emeritus
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman at es.net