nixos/buildbot: don't require network-online.target

The daemon setup itself only requires the firewall to be up.
Workers will connect itself as they can reach the master instance.
That's why we don't need an online target for buildbot to function.

nixos/modules/services/continuous-integration/buildbot/master.nix

@@ -267,8 +267,7 @@ in {
 
     systemd.services.buildbot-master = {
       description = "Buildbot Continuous Integration Server.";
-      after = [ "network-online.target" ];
-      wants = [ "network-online.target" ];
+      after = [ "network.target" ];
       wantedBy = [ "multi-user.target" ];
       path = cfg.packages ++ cfg.pythonPackages python.pkgs;
       environment.PYTHONPATH = "${python.withPackages (self: cfg.pythonPackages self ++ [ package ])}/${python.sitePackages}";