removed WidgetsFlutterBinding.ensureInitialized()

- This blocks error reporting via runZonedGuarded
- Also this is should be called before calling runApp method via
main method

@@ -24,7 +24,6 @@ class MobileScannerWebPlugin {
       registrar,
     );
     final MobileScannerWebPlugin instance = MobileScannerWebPlugin();
-    WidgetsFlutterBinding.ensureInitialized();
 
     channel.setMethodCallHandler(instance.handleMethodCall);
     event.setController(instance.controller);