Extractor_ruian Cache too many open files

[ghost]

https://github.com/mff-uk/DPUs/blob/feature/rdf_rework/ruian/src/main/java/cz/cuni/mff/xrg/scraper/css_parser/utils/Cache.java

private static void download_and_gunzip(String fromURL, File toFile) throws IOException
{
GZIPInputStream gis = null;
try {
URL oURL = new URL(fromURL);
OutputStream fos = new FileOutputStream(toFile);
InputStream is = oURL.openStream();
gis = new GZIPInputStream(is);

IOUtils.copy(gis, fos);
} finally {
if (gis != null) {
gis.close();
}
}
}

nobody closes fos