Add network group to tls-backend

In case of a deployment utilising network nodes the backend TLS
configuration is missing on network nodes.

Closes-Bug: #2117084

Change-Id: Ie5247cbcc81388d67707b0772ae00fda8ab7262b
Signed-off-by: Michal Nasiadka <[email protected]>
(cherry picked from commit 9d3bf14)

Author: mnasiadka

ansible/roles/kolla-ansible/templates/overcloud-components.j2

@@ -15,6 +15,7 @@ bifrost
 
 [tls-backend:children]
 control
+network
 
 # You can explicitly specify which hosts run each project by updating the
 # groups in the sections below. Common services are grouped together.

releasenotes/notes/bug-2117084-8d1eaa375df1d1f8.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Fixes configuration of backend TLS when network nodes are separate from
+    controllers.
+    `LP#2117084 <https://bugs.launchpad.net/kayobe/+bug/2117084>`__