Hi, any reason why [`c49cb1f`](https://github.com/kornelski/pngquant/commit/c49cb1f8f7a0a85ad20fd7481d376863e0b0c8db) (#408) was not applied to `3.x` / the `main` branch? At a quick glance it looks like it would be [applicable there as well](https://github.com/kornelski/pngquant/blob/3.0.3/rwpng.c#L147).