Update mirrors from apt to mirror.mirantis.com

Change-Id: I856859a7bf2a1cc2d12fcb965e3b69c2a580cd2f
diff --git a/day01-image/scripts/salt.sh b/day01-image/scripts/salt.sh
index 25fda6e..7ec442a 100644
--- a/day01-image/scripts/salt.sh
+++ b/day01-image/scripts/salt.sh
@@ -1,7 +1,7 @@
 #!/bin/bash -xe
 
 MCP_VERSION=${MCP_VERSION:-proposed}
-APT_MIRANTIS_SALT_REPO=${APT_MIRANTIS_SALT_REPO:-"http://apt.mirantis.com/xenial/ $MCP_VERSION salt"}
+APT_MIRANTIS_SALT_REPO=${APT_MIRANTIS_SALT_REPO:-"http://mirror.mirantis.com/${MCP_VERSION}/salt-formulas/xenial xenial main"}
 SALT_OPTS="-t 10 --retcode-passthrough --no-color"
 
 echo "deb [arch=amd64] ${APT_MIRANTIS_SALT_REPO}" > /etc/apt/sources.list.d/mcp_salt.list