minor fix

lib/main_common.dart

@@ -33,6 +33,7 @@ void mainCommon(AppFlavor flavor) {
   // - in profile/release mode: plain grey background
   // This can be modified via `ErrorWidget.builder`
   // ErrorWidget.builder = (details) => ErrorWidget(details.exception);
+  // cf https://docs.flutter.dev/testing/errors
 
   runApp(AvesApp(flavor: flavor));
 }

lib/widgets/aves_app.dart

@@ -380,10 +380,10 @@ class _AvesAppState extends State<AvesApp> with WidgetsBindingObserver {
       'locales': WidgetsBinding.instance.window.locales.join(', '),
       'time_zone': '${now.timeZoneName} (${now.timeZoneOffset})',
     });
-    _navigatorObservers = [
-      AvesApp.pageRouteObserver,
-      ReportingRouteTracker(),
-    ];
+    setState(() => _navigatorObservers = [
+          AvesApp.pageRouteObserver,
+          ReportingRouteTracker(),
+        ]);
   }
 
   void _onNewIntent(Map? intentData) {