Fix keystone interface value

PROD-34078
PROD-30591

Change-Id: Ia8367afe43bf6911bc5577ef3363da0ed970702c
diff --git a/nova/files/pike/nova-controller.conf.Debian b/nova/files/pike/nova-controller.conf.Debian
index 8f6eacd..abf07f2 100644
--- a/nova/files/pike/nova-controller.conf.Debian
+++ b/nova/files/pike/nova-controller.conf.Debian
@@ -5795,7 +5795,7 @@
 
 
 [keystone]
-interface = controller.identity.get('interface', 'internal')
+interface = {{ controller.identity.get('interface', 'internal') }}
 {%- if controller.identity.valid_interfaces is defined %}
 {%-   set valid_interfaces = controller.identity.valid_interfaces|join(',') %}
 {%- else %}