Move the common URL part into image_url_prefix

Signed-off-by: Andrej Shadura <andrew.shadura@collabora.co.uk>

Jenkinsfile

@@ -17,8 +17,10 @@ upload_root = "/srv/images/" + (production ? "public" : "test/${env.JOB_NAME}")
 upload_dest = "${upload_host}:${upload_root}"
 upload_credentials = '5a23cd79-e26d-41bf-9f91-d756c131b811'
 
+image_url_prefix = "https://images.apertis.org" + (production ? "" : "/test/${env.JOB_NAME}")
+
 ostree_path = "ostree/repo/"
-ostree_pull_url = "https://images.apertis.org" + (production ? "" : "/test/${env.JOB_NAME}") + "/${ostree_path}"
+ostree_pull_url = image_url_prefix + "/${ostree_path}"
 
 test_repo_url = "git@gitlab.apertis.org:infrastructure/apertis-tests.git"
 test_repo_credentials = 'df7b609b-df30-431d-a942-af263af80571'
@@ -27,7 +29,7 @@ test_lava_credentials = 'apertis-lava-user'
 
 demopack = "https://images.apertis.org/media/multimedia-demo.tar.gz"
 
-sysroot_url_prefix = "https://images.apertis.org/" + (production ? "" : "test/${env.JOB_NAME}/") + "sysroot/"
+sysroot_url_prefix = image_url_prefix + "/sysroot/"
 
 def architectures = [
     amd64: [