Made Settings persistent with autosave

lib/app.dart

@@ -21,6 +21,7 @@ class App extends StatefulWidget {
 
 class _AppState extends State<App> {
   int currentPage = 0;
+  late Timer refetchChats;
 
   @override
   void initState() {
@@ -29,7 +30,8 @@ class _AppState extends State<App> {
     WidgetsBinding.instance.addPostFrameCallback((timeStamp) {
       Provider.of<ChatListProps>(context, listen: false).run();
     });
-    Timer.periodic(const Duration(minutes: 1), (timer) {
+    refetchChats = Timer.periodic(const Duration(minutes: 1), (timer) {
+      if(!context.mounted) return;
       Provider.of<ChatListProps>(context, listen: false).run();
     });
 
@@ -101,4 +103,10 @@ class _AppState extends State<App> {
     );
 
   }
+
+  @override
+  void dispose() {
+    refetchChats.cancel();
+    super.dispose();
+  }
 }