Use on-marked-down shutdown-sessions for redis haproxy conf
Use on-marked-down shutdown-sessions for redis haproxy conf

The problem we have with redis can be described as follows:
- Connection is made to redis via haproxy, where haproxy directs to one redis node
- That chosen redis node fails and a new redis node gets promoted
- HAProxy will send *new* connections to redis to the newly promoted
  redis server, but you still have a session active (ie. that has not hit
  timeout), so haproxy will attempt to use that connection.

By using 'on-marked-down shutdown-sessions' we make sure we close
old existing sessions when the redis master node changes.

Closes-Bug: #1742086
Tested-By: Marian Krcmarik <mkrcmari@redhat.com>

Change-Id: Ia4d8c27057ee2de9e49e4358aa069571d1c952a9

openstack/puppet-tripleo,openstack/puppet-tripleo,openstack/puppet-tripleo