syncthing: start tray after syncthing.service

Fixes #2963

modules/services/syncthing.nix

@@ -98,7 +98,11 @@ in {
           Unit = {
             Description = cfg.tray.package.pname;
             Requires = [ "tray.target" ];
-            After = [ "graphical-session-pre.target" "tray.target" ];
+            After = [
+              "graphical-session-pre.target"
+              "tray.target"
+              "syncthing.service"
+            ];
             PartOf = [ "graphical-session.target" ];
           };
 
@@ -118,7 +122,11 @@ in {
           Unit = {
             Description = "syncthingtray";
             Requires = [ "tray.target" ];
-            After = [ "graphical-session-pre.target" "tray.target" ];
+            After = [
+              "graphical-session-pre.target"
+              "tray.target"
+              "syncthing.service"
+            ];
             PartOf = [ "graphical-session.target" ];
           };