Fix repository configuration to match system reclass

Change-Id: Iecde194c92dc3037523349af689e720770f8dc68
diff --git a/ubuntu-16.04/scripts/docker.sh b/ubuntu-16.04/scripts/docker.sh
index 05c9b31..4855416 100644
--- a/ubuntu-16.04/scripts/docker.sh
+++ b/ubuntu-16.04/scripts/docker.sh
@@ -4,7 +4,8 @@
 apt-get -y install curl
 
 # Add apt-mk repository
-echo "deb [arch=amd64] http://apt-mk.mirantis.com/xenial/ nightly extra salt" > /etc/apt/sources.list.d/apt-mk.list
+echo "deb [arch=amd64] http://apt-mk.mirantis.com/xenial/ nightly salt" > /etc/apt/sources.list.d/mcp_salt.list
+echo "deb [arch=amd64] http://apt-mk.mirantis.com/xenial/ nightly extra" > /etc/apt/sources.list.d/mcp_extra.list
 curl -sf http://apt-mk.mirantis.com/public.gpg | apt-key add -
 
 apt-get clean