Comment 4 for bug 1369386

FWIW I pushed this TripleO patch to install ipset in parallel:

https://review.openstack.org/#/c/121435/

I still disagree that this should be enabled by default for the reasons I previously mentioned. If this broke us in TripleO it'll likely cause someone else pain too. You could easily increase the testing footprint via other means... without just automatically enabling it like this.