Fix typo for rabbitmq transport url

Change-Id: I73bc13d71cc348810690ad64e697a8d3c95898f7
Related-Prod: PROD-25236
diff --git a/nova/controller.sls b/nova/controller.sls
index b67926e..e6dbac5 100644
--- a/nova/controller.sls
+++ b/nova/controller.sls
@@ -347,7 +347,7 @@
   - name: "cell1"
   - db_name: {{ controller.database.name }}
 {%- if controller.message_queue.members is defined %}
-  - transport_url = rabbit://{% for member in controller.message_queue.members -%}
+  - transport_url: rabbit://{% for member in controller.message_queue.members -%}
                              {{ controller.message_queue.user }}:{{ controller.message_queue.password }}@{{ member.host }}:{{ member.get('port', rabbit_port) }}
                              {%- if not loop.last -%},{%- endif -%}
                          {%- endfor -%}