nixos-module/container/dns: set notify-source for zone xfer

nix/nixos-module/container/dns.nix

@@ -101,6 +101,8 @@ in
               95.217.229.209;
               2a01:4f9:4b:39ec::4;
             };
+            notify-source ${config.site.net.serv.hosts4.dns};
+            notify-source-v6 ${config.site.net.serv.hosts6.up1.dns};
           '' + lib.optionalString dynamic ''
             allow-update { key "dyndns"; };
           '';