Added code to reset the chess set to the default if it is no longer present when starting the app.
Added code to reset the chess set to the default if it is no longer present when starting the app.

NightSwimming/Raptor-Chess,NightSwimming/Raptor-Chess,raptor-chess/raptor-chess-interface,NightSwimming/Raptor-Chess,raptor-chess/raptor-chess-interface,evilwan/raptor-chess-interface,raptor-chess-interface/raptor-chess-interface,NightSwimming/Raptor-Chess,evilwan/raptor-chess-interface,raptor-chess-interface/raptor-chess-interface,evilwan/raptor-chess-interface,raptor-chess/raptor-chess-interface,raptor-chess/raptor-chess-interface,evilwan/raptor-chess-interface,raptor-chess-interface/raptor-chess-interface,raptor-chess-interface/raptor-chess-interface