Changing vault key in existing box gives HiveError

Changing the secure key of an existing `box` in

```dart
await Hive.openBox(vaultFile, encryptionCipher: HiveAesCipher(secureKey));
```

gives `HiveError (HiveError: This should not happen. Please open an issue on GitHub.)`

```bash
flutter doctor
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, 2.2.3, on macOS 11.5.2 20G95 darwin-x64, locale de-DE)
[✓] Android toolchain - develop for Android devices (Android SDK version 31.0.0)
[✓] Xcode - develop for iOS and macOS
[✓] Chrome - develop for the web
[✓] Android Studio (version 2020.3)
[✓] VS Code (version 1.59.0)
[✓] Connected device (2 available)
```

```bash
hive: 2.0.4
hive_flutter: 1.1.0
flutter_secure_storage: 4.2.1
```

This happens just while coding, but it should be reported to catch the error.