Change apt_mk_version => mcp_version

   * Alligh all variables to one
   * Due mcp_version: ${_param:apt_mk_version}
     those change still bw compatible

Bug-relateted: PROD-24789 (PROD:24789)
Change-Id: I30b6fb0b1cb66c7d56dbb3a5e15c8bc9606405b5
diff --git a/aptly/server/mirror/ubuntu/xenial/salt.yml b/aptly/server/mirror/ubuntu/xenial/salt.yml
index c209710..1c1f5ab 100644
--- a/aptly/server/mirror/ubuntu/xenial/salt.yml
+++ b/aptly/server/mirror/ubuntu/xenial/salt.yml
@@ -17,4 +17,4 @@
           publisher:
             component: salt
             distributions:
-              - ubuntu-xenial/${_param:apt_mk_version}
\ No newline at end of file
+              - ubuntu-xenial/${_param:mcp_version}
\ No newline at end of file