Extended description of OPENSTACK_HOST setting
This change extends the description of OPENSTACK_HOST, now including
references to other settings that explain how to setup multiple region in
Horizon.
@@ -807,6 +807,10 @@ The hostname of the Keystone server used for authentication if you only have
one region. This is often the *only* setting that needs to be set for a
basic deployment.
+If you have multiple regions you should use the ``AVAILABLE_REGIONS`` setting
+instead.
+
+
.. _hypervisor-settings-label:
``OPENSTACK_HYPERVISOR_FEATURES``
