[maven-release-plugin] rollback the release of RoaringBitmap-0.6.20
[maven-release-plugin] rollback the release of RoaringBitmap-0.6.20

RoaringBitmap/RoaringBitmap,lemire/RoaringBitmap,okrische/RoaringBitmap,lemire/RoaringBitmap,okrische/RoaringBitmap,RoaringBitmap/RoaringBitmap,lemire/RoaringBitmap,RoaringBitmap/RoaringBitmap,lemire/RoaringBitmap,RoaringBitmap/RoaringBitmap,okrische/RoaringBitmap