Enable ironic ui when enable_ironic is yes

Depends-On: Ie094b92b9a8e20696cee84698013d09306dd6e7f
Change-Id: Ib1bbf1e5cb1536a41ab8c3082026ba90811f8df7
Closes-Bug: #1645104

ansible/roles/horizon/tasks/start.yml

@@ -6,6 +6,7 @@
     image: "{{ horizon_image_full }}"
     name: "horizon"
     environment:
+      ENABLE_IRONIC: "{{ 'yes' if enable_ironic | bool else 'no' }}"
       ENABLE_MANILA: "{{ 'yes' if  enable_manila | bool else 'no' }}"
       ENABLE_NEUTRON_LBAAS: "{{ 'yes' if  enable_neutron_lbaas | bool else 'no' }}"
     volumes: