[www] Enable config-reference for icehouse and juno
[www] Enable config-reference for icehouse and juno

For EOL'ed juno and newer distros keep the Config-reference and redirect
everything else.

Change-Id: I02acb6acf246fb45e78fabafaa5b13e28030e98b

openstack/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals