getx Nested routing bug

getx Nested routing bug
source code: https://github.com/liseipi/demo1.git

example:

```index.dart
class IndexPage extends GetView {
const IndexPage({Key? key}) : super(key: key);

@override
Widget build(BuildContext context) {
return Scaffold(
body: Navigator(
key: Get.nestedKey(1),
initialRoute: '/home',
onGenerateRoute: controller.onGenerateRoute,
),
bottomNavigationBar: Obx(
() => BottomNavigationBar(
items: const [
BottomNavigationBarItem(
icon: Icon(Icons.home),
label: 'Home',
),
BottomNavigationBarItem(
icon: Icon(Icons.account_circle),
label: 'My',
),
],
currentIndex: controller.currentIndex.value,
selectedItemColor: Colors.pink,
onTap: controller.changePage,
),
),
);
}
}
```

```home.dart
class HomePage extends GetView {
const HomePage({Key? key}) : super(key: key);

@override
Widget build(BuildContext context) {
return Navigator(
key: Get.nestedKey(2),
initialRoute: '/recommend',
onGenerateRoute: controller.onGenerateRoute,
);
}
}
```

**To Reproduce**
Steps to reproduce the behavior:
1. Click BottomNavigation change
2. show error

```
The following assertion was thrown while finalizing the widget tree:
Duplicate GlobalKey detected in widget tree.

The following GlobalKey was specified multiple times in the widget tree. This will lead to parts of the widget tree being truncated unexpectedly, because the second time a key is seen, the previous instance is moved to the new location. The key was:

```

**Minimal reproduce code**
My smallest source code address： https://github.com/liseipi/demo1.git