mta_sts: Use CRLF line terminators per the RFC[1]

[1] https://datatracker.ietf.org/doc/html/rfc8461#section-3.2

roles/mta_sts/templates/nginx.d.conf.j2

@@ -33,7 +33,7 @@ server {
     location = /.well-known/mta-sts.txt {
         default_type text/plain;
         # Remember to bump the MTA-STS id in tf-stage1/archlinux.tf
-        return 200 'version: STSv1\nmode: enforce\nmax_age: 2592000\nmx: {{ config.mx | join('\\nmx: ')}}\n';
+        return 200 'version: STSv1\r\nmode: enforce\r\nmax_age: 2592000\r\nmx: {{ config.mx | join('\\r\\nmx: ')}}\r\n';
     }
 
     location / {

tf-stage1/archlinux.tf

@@ -194,7 +194,7 @@ locals {
     "_smtp._tls.master-key" = { value = "v=TLSRPTv1;rua=mailto:postmaster@archlinux.org" }
     "_smtp._tls.lists"      = { value = "v=TLSRPTv1;rua=mailto:postmaster@archlinux.org" }
     # Generated with: date +%Y%m%d01
-    "_mta-sts"   = { value = "v=STSv1; id=2022051601" }
+    "_mta-sts"   = { value = "v=STSv1; id=2022051602" }
     "@"          = { value = "v=spf1 ip4:${hcloud_server.machine["mail.archlinux.org"].ipv4_address} ip6:${hcloud_server.machine["mail.archlinux.org"].ipv6_address} ~all" }
     "mail"       = { value = "v=spf1 ip4:${hcloud_server.machine["mail.archlinux.org"].ipv4_address} ip6:${hcloud_server.machine["mail.archlinux.org"].ipv6_address} ~all" }
     "aur"        = { value = "v=spf1 ip4:${hcloud_server.machine["mail.archlinux.org"].ipv4_address} ip6:${hcloud_server.machine["mail.archlinux.org"].ipv6_address} ~all" }