Disable ACME DNS propagation check for Cloudflare

Cloudflare is the authoritative NS so API-created TXT records are
immediately visible — the propagation poll was timing out unnecessarily.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

services/nginx.nix

@@ -64,6 +64,7 @@ in
         domain = "*.nordhammer.it";
         extraDomainNames = [ "nordhammer.it" ];
         dnsProvider = "cloudflare";
+        dnsPropagationCheck = false;
         credentialFiles = {
           "CF_DNS_API_TOKEN_FILE" = "/var/secrets/cloudflare-token";
         };