Fix serialization errors when hosting MP game.
Follows D2746 / rP24462 and rP24167.
Player colors are copied from the settings, which are deep-frozen, thus not extensible. Cloning them restores that, allowing serialization.
Reported By: Angen
Differential Revision: https://code.wildfiregames.com/D3263
I think we should have a comment for modders, why they need to write like this. At the moment it seems like a workaround for them.