message: Fix unused variable warning in release build
diff: @@ -25,6 +25,7 @@ struct RawStruct<RPG::Rect> {
  */
  void RawStruct<RPG::Rect>::ReadLcf(RPG::Rect& ref, LcfReader& stream, uint32_t length) {
  assert(length == 16);
  + (void)length;
  stream.Read(ref.l);
  stream.Read(ref.t);
  stream.Read(ref.r);
  