added ScaffoldMessenger

lib/screens/settings/screen_settings.dart

@@ -12,7 +12,8 @@ class SettingsScreen extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    return SliverScreen(
+    return ScaffoldMessenger(
+      child: SliverScreen(
         title: S.of(context).settings,
         appBarActions: [
           IconButton(
@@ -33,6 +34,7 @@ class SettingsScreen extends StatelessWidget {
             ),
           ),
         ],
+      ),
     );
   }
 }