Fix the Tempest image url variable

Seems very strange the variable of the image url doeesn't have the
correct prefix. This trivial fix will solve the issue.

TrivialFix

Change-Id: Ib5a073d5b8209005be8841e355e75047c77bd488
Signed-off-by: Maksim Malchuk <[email protected]>
(cherry picked from commit d6e14f8)

Author: mmalchuk

ansible/roles/tempest/defaults/main.yml

@@ -31,7 +31,7 @@ tempest_extra_volumes: "{{ default_extra_volumes }}"
 ###########################
 # Tempest Required Resource
 ###########################
-image_url: "https://github.com/cirros-dev/cirros/releases/download/0.5.1/cirros-0.5.1-x86_64-disk.img"
+tempest_image_url: "{{ image_url | default('https://github.com/cirros-dev/cirros/releases/download/0.5.1/cirros-0.5.1-x86_64-disk.img') }}"
 
 tempest_image_id:
 tempest_image_alt_id: "{{ tempest_image_id }}"

ansible/roles/tempest/templates/tempest.conf.j2

@@ -41,7 +41,7 @@ ca_certificates_file = {{ openstack_cacert }}
 
 [image]
 region = {{ openstack_region_name }}
-http_image = {{ image_url }}
+http_image = {{ tempest_image_url }}
 
 [image-feature-enabled]
 api_v1 = False