Hardcode app title

lib/l10n/app_en.arb

@@ -1,5 +1,4 @@
 {
-  "mainTitle": "Traccar Client",
   "trackingTitle": "Tracking",
   "settingsTitle": "Settings",
   "statusTitle": "Logs",

lib/main_screen.dart

@@ -134,7 +134,7 @@ class _MainScreenState extends State<MainScreen> {
   Widget build(BuildContext context) {
     return Scaffold(
       appBar: AppBar(
-        title: Text(AppLocalizations.of(context)!.mainTitle),
+        title: Text('Traccar Client'),
       ),
       body: SingleChildScrollView(
         padding: const EdgeInsets.all(16.0),