Add ovn_sb_connection to octavia.conf

This commit added ovn_sb_connection to octavia.conf otherwise it will
try to connect to ovn-sb-db using the default address which is
127.0.0.1 while the ovn-sb-db listen on the IP address of the
api_interface.

Closes-Bug: #1950111

Change-Id: I9cb9a0365d00ffd70562b4b3e83493ec09bd52c2
(cherry picked from commit 1077a9a)

Author: ching-kuo

ansible/roles/octavia/templates/octavia.conf.j2

@@ -28,6 +28,7 @@ enabled_provider_agents = {{ octavia_provider_agents }}
 {% if neutron_plugin_agent == 'ovn' %}
 [ovn]
 ovn_nb_connection = {{ ovn_nb_connection }}
+ovn_sb_connection = {{ ovn_sb_connection }}
 {% endif %}
 
 [haproxy_amphora]

releasenotes/notes/bug-1950111-8e477fb6a5b58822.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Fixes Octavia's "Connection refused" errors by adding ``ovn_sb_connection``
+    to ``octavia.conf``.
+    `LP#195011 <https://launchpad.net/bugs/195011>`__