fix: linux system tray tooltip (#243)

ui/flutter/lib/app/modules/app/controllers/app_controller.dart

@@ -202,7 +202,10 @@ class AppController extends GetxController with WindowListener, TrayListener {
         onClick: (menuItem) => {windowManager.destroy()},
       ),
     ]);
-    await trayManager.setToolTip('Gopeed');
+    if (!Util.isLinux()) {
+      // Linux seems not support setToolTip, refer to: https://github.com/GopeedLab/gopeed/issues/241
+      await trayManager.setToolTip('Gopeed');
+    }
     await trayManager.setContextMenu(menu);
     trayManager.addListener(this);
   }

ui/flutter/lib/util/util.dart

@@ -93,6 +93,10 @@ class Util {
     return !kIsWeb && Platform.isMacOS;
   }
 
+  static isLinux() {
+    return !kIsWeb && Platform.isLinux;
+  }
+
   static isWeb() {
     return kIsWeb;
   }