Added workaround to load native library from already unzipped folder

This is an odd one, but Hadoop for some reason pre-unzips the .jar files for its jobs, and so the native .so loading logic fails with a ZIP exception. You can argue this is Hadoop being weird, and I'd nod along, but this patch fixes the issue I was running into. Feel free to ignore this pull, I just wanted to get this workaround into the collective github consciousness! :)