Update model for offline image

* Fix typos for default offline images names
* Update debmirror repos
* Add entropy for aptly container
* Update MAAS configs

Change-Id: I700216f3727023a36e579da08c0f416b67a94cf8
Related-Prod: PROD-32735
diff --git a/maas/region/single.yml b/maas/region/single.yml
index 309ef34..601b883 100644
--- a/maas/region/single.yml
+++ b/maas/region/single.yml
@@ -4,7 +4,7 @@
 parameters:
   _param:
     maas_admin_username: mirantis
-    maas_region_main_archive: http://mirror.mirantis.com/${_param:mcp_version}/ubuntu/
+    maas_region_main_archive: ${_param:linux_system_repo_update_url}/ubuntu/
   maas:
     cluster:
       enabled: true