Stop deleting-and-creating RabbitMQ account

The `force` option creates and recreates the user which means on
any deploy it kills *all* AMQP traffic on all agents.

This updates it when changed every single run, which shouldn't
kill the connectivity when we run playbooks.

Change-Id: I5c2478b41d49dd3e4392c1800ad6a7e7c1494152
Closes-Bug: 1825329

sync/tasks/mq_setup.yml

@@ -86,12 +86,12 @@
       rabbitmq_user:
         user: "{{ _oslomsg_notify_userid }}"
         password: "{{ _oslomsg_notify_password }}"
+        update_password: always
         vhost: "{{ _oslomsg_notify_vhost }}"
         configure_priv: ".*"
         read_priv: ".*"
         write_priv: ".*"
         state: "present"
-        force: true
       no_log: true
       when:
         - (_oslomsg_rpc_userid is undefined) or