Add default SALT_MASTER_URL for deploy pipeline

Change-Id: I81ec2baba919da2ff3bc1cfdef90d78e01bf692d
diff --git a/jenkins/client/job/deploy/openstack.yml b/jenkins/client/job/deploy/openstack.yml
index 3595e01..2e89659 100644
--- a/jenkins/client/job/deploy/openstack.yml
+++ b/jenkins/client/job/deploy/openstack.yml
@@ -1,4 +1,6 @@
 parameters:
+  _param:
+    jenkins_salt_api_url: "http://${_param:salt_master_host}:6969"
   jenkins:
     client:
       job:
@@ -31,7 +33,7 @@
               default: "salt"
             SALT_MASTER_URL:
               type: string
-              default: ""
+              default: "${_param:jenkins_salt_api_url}"
             ASK_ON_ERROR:
                 type: boolean
                 default: 'false'