synit: fixup ntp service

nixos/modules/synit/services/ntpd.nix

@@ -2,13 +2,14 @@
 
 {
   config = lib.mkIf config.services.ntp.enable {
-    environment.etc."syndicate/services/ssh-keygen.pr".text = let
-      serverList =
-        lib.lists.concatMap (s: " -p ${s}") config.networking.timeServers;
-    in ''
-      <require-service <daemon ntpd>>
-      <depends-on <daemon ntpd> <default-route ipv4>>
-      <daemon ntpd "${pkgs.busybox}/bin/busybox ntpd -d -n ${serverList}">
-    '';
+    environment.etc."syndicate/services/ntpd.pr".text =
+      let serverList = map (s: " -p ${s}") config.networking.timeServers;
+      in ''
+        <require-service <daemon ntpd>>
+        <depends-on <daemon ntpd> <default-route ipv4>>
+        <daemon ntpd "${pkgs.busybox}/bin/busybox ntpd -d -n ${
+          toString serverList
+        }">
+      '';
   };
 }