Add os_region_name config option

In a multi-region shared keystone deployment, we must set the
os_region_name config option. Without it, Masakari will try to connect
to the wrong API endpoints when it needs to talk to other services.

Closes-Bug: #2042924

Change-Id: I31ae1e011354fc9ded114babcb92f366256fadea
Signed-off-by: Gabriel Adrian Samfira <gsamfira@cloudbasesolutions.com>

src/templates/stein/masakari.conf

@@ -4,6 +4,10 @@ debug = {{ options.debug }}
 auth_strategy = keystone
 notification_driver=taskflow_driver
 
+{% if options.region -%}
+os_region_name = {{ options.region }}
+{% endif -%}
+
 {% if amqp.password -%}
 {% include "parts/section-transport-url" %}
 {% endif -%}