fix libFLAC encoder to default to compression level 5 (SF#1816825: https://sourceforge.net/tracker2/?func=detail&aid=1816825&group_id=13478&atid=113478)
fix libFLAC encoder to default to compression level 5 (SF#1816825: https://sourceforge.net/tracker2/?func=detail&aid=1816825&group_id=13478&atid=113478)

jeeb/flac,jeeb/flac,jeeb/flac,jeeb/flac