Fix MSVC warning C26493

Relating to C++ Core Guidelines type.4, but returning a value at all is
inappropriate.

src/api/game/load_order_handler.cpp

@@ -51,7 +51,7 @@ unsigned int mapGameId(GameType gameType) {
     case GameType::fo4vr:
       return LIBLO_GAME_FO4VR;
     default:
-      return (unsigned int)-1;
+      throw std::logic_error("Unexpected game type");
   }
 }