Mount /etc/openldap inside the keystone container

For configuring high availability for LDAP in keystone one
needs to edit /etc/openldap/ldap.conf. This worked
before control plane was containerised. Mounting the
openldap configuration into the keystone container
restores the previous behavior.

Change-Id: Id0d73a8ab0ddf7bf9e2b76ea14ffc9acff3a0ad3
Closes-Bug: #1923048
Resolves: rhbz#1944466

deployment/keystone/keystone-container-puppet.yaml

@@ -663,6 +663,7 @@ outputs:
                 - {get_attr: [ContainersCommon, volumes]}
                 - {get_attr: [KeystoneLogging, volumes]}
                 -
+                  - /etc/openldap:/etc/openldap:ro
                   - /var/lib/kolla/config_files/keystone.json:/var/lib/kolla/config_files/config.json:ro
                   - /var/lib/config-data/puppet-generated/keystone:/var/lib/kolla/config_files/src:ro
                 - if: