Use salt pre-set image from prod registry

Docker-prod registry is public available, so lets switch salt
prebuilt image to use from that registry.

Change-Id: I1d8b681be8295b6bd25272de3e371b0de9c1e4ee
Related-Prod: PROD-27660 (PROD-27660)
diff --git a/src/com/mirantis/mk/SaltModelTesting.groovy b/src/com/mirantis/mk/SaltModelTesting.groovy
index aad9524..6a6604b 100644
--- a/src/com/mirantis/mk/SaltModelTesting.groovy
+++ b/src/com/mirantis/mk/SaltModelTesting.groovy
@@ -33,7 +33,7 @@
     def dockerContainerName = config.get('dockerContainerName', defaultContainerName)
     //  def dockerImageName = config.get('image', "mirantis/salt:saltstack-ubuntu-xenial-salt-2017.7")
     // FIXME /PROD-25244
-    def dockerImageName = config.get('image', "docker-dev-virtual.docker.mirantis.net/mirantis/salt:saltstack-ubuntu-xenial-salt-2017.7")
+    def dockerImageName = config.get('image', "docker-prod-virtual.docker.mirantis.net/mirantis/salt:saltstack-ubuntu-xenial-salt-2017.7")
     def dockerMaxCpus = config.get('dockerMaxCpus', 4)
     def dockerExtraOpts = config.get('dockerExtraOpts', [])
     def envOpts = config.get('envOpts', [])