[boost] Mailman upgrade

All, Per https://bugs.launchpad.net/mailman/+bug/1747209, Ciere staff will install 2.1.26 beginning 9-Feb-2018 04:00 UTC. While the maintenance is performed, incoming messages to the mailing lists for Boost will be temporarily blocked. This may result in “temporarily unable to deliver” messages received by senders if a message is delivered during the upgrade. The upgrade is expected to finish by 9-Feb-2018 05:00 UTC. Thanks, Brad Johnson Your Friendly Mailing List Admin