rundeck: run as deployer

nix/pkgs/rundeck-bin/module.nix

@@ -19,6 +19,7 @@ in {
       wantedBy = [ "multi-user.target" ];
       after = [ "network.target" ];
       serviceConfig = {
+        User = "deployer";
         ExecStart = "${cfg.package}/bin/rundeckd -b /var/lib/rundeck";
         StateDirectory = "rundeck";
       };