Update mirrors from apt to mirror.mirantis.com

Change-Id: I856859a7bf2a1cc2d12fcb965e3b69c2a580cd2f
diff --git a/mirror-image/template.json b/mirror-image/template.json
index 4469b8a..f7e668b 100644
--- a/mirror-image/template.json
+++ b/mirror-image/template.json
@@ -14,7 +14,7 @@
     "ubuntu_baseurl": "{{ env `UBUNTU_BASEURL` }}",
     "saltstack_gpg": "{{ env `SALTSTACK_GPG` }}",
     "saltstack_repo": "{{ env `SALTSTACK_REPO` }}",
-    "apt_mirantis_gpg": "{{ env `APT_MIRANTIS_GPG` }}",
+    "apt_mirantis_gpg": "{{ env `APT_MIRANTIS_SALT_GPG` }}",
     "apt_mirantis_salt_repo": "{{ env `APT_MIRANTIS_SALT_REPO` }}",
     "git_salt_formulas_scripts": "{{ env `GIT_SALT_FORMULAS_SCRIPTS` }}",
     "os_flavor": "27574e15-f031-4b78-a82d-4cef3aea9442",
@@ -53,7 +53,7 @@
         "UBUNTU_BASEURL={{ user `ubuntu_baseurl` }}",
         "SALTSTACK_GPG={{ user `saltstack_gpg` }}",
         "SALTSTACK_REPO={{ user `saltstack_repo` }}",
-        "APT_MIRANTIS_GPG={{ user `apt_mirantis_gpg` }}",
+        "APT_MIRANTIS_SALT_GPG={{ user `apt_mirantis_gpg` }}",
         "APT_MIRANTIS_SALT_REPO={{ user `apt_mirantis_salt_repo` }}",
         "GIT_SALT_FORMULAS_SCRIPTS={{ user `git_salt_formulas_scripts` }}",
         "PACKER_OFFLINE_BUILD=true"