"multiplayer.player.changeToSkin" translation appears "their" when the object is only one player

Steps to Reproduce:

Open a world and ask one of your friends to join in. Ask him/her to change his/her skin.

Observed Result:

You'll see "%s has changed their skin."

Expected Result:

I think %s refers to one player, and therefore "their" shouldn't be used. Instead, you can use "%s has changed his/her skin."