Solum: remove oslo_messaging_notifications config

Solum doesn't use notification

Change-Id: I0f82d0259e1adc7b89558f9bb8864eaa731dd863

ansible/roles/solum/templates/solum.conf.j2

@@ -59,6 +59,3 @@ memcached_servers = {% for host in groups['memcached'] %}{{ hostvars[host]['ansi
 
 [oslo_messaging_rabbit]
 transport_url = rabbit://{% for host in groups['rabbitmq'] %}{{ rabbitmq_user }}:{{ rabbitmq_password }}@{% if orchestration_engine == 'KUBERNETES' %}rabbitmq{% else %}{{ hostvars[host]['ansible_' + hostvars[host]['api_interface']]['ipv4']['address'] }}{% endif %}:{{ rabbitmq_port }}{% if not loop.last %},{% endif %}{% endfor %}
-
-[oslo_messaging_notifications]
-driver = messagingv2