Inner class referenced via `Outer.Inner` is no longer mapped

[Johni0702]

https://github.com/Johni0702/BetterPortals/blob/faa6d07e554af1965ca63d529cd624a21a85c571/src/view/kotlin/de/johni0702/minecraft/view/impl/client/ClientWorldsManagerImpl.kt#L237-L242