Replace Minetest mentions with Luanti (#3169)

mods/bones/license.txt

@@ -3,7 +3,7 @@ License of source code
 
 The MIT License (MIT)
 Copyright (C) 2012-2016 PilzAdam
-Copyright (C) 2012-2016 Various Minetest developers and contributors
+Copyright (C) 2012-2016 Various Minetest Game developers and contributors
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of this
 software and associated documentation files (the "Software"), to deal in the Software