fix: window index field lookup

[SocialMoods]

This PR fixes issue when Player class has been changed during PlayerCreationEvent:

    @EventHandler
    public void onPlayerCreation(PlayerCreationEvent event) {
        // inject proxy to handleDataPacket method
        event.setPlayerClass(SyncPlayer.class);
    }

public class SyncPlayer extends Player 

[KoshakMineDEV]

#3