Comment 4 for bug 1735691

I've placed updated packages for xenial, zesty and artful into:

  https://launchpad.net/~ci-train-ppa-service/+archive/ubuntu/3067

I've tested upgrades of the xenial packages in a three unit pxc cluster; each unit was upgrade in turn, correctly re-joining the cluster and re-syncing with the other two units.

I'll re-test all three against the actual security-proposed packages.