Revert "PUBEV-2953: Add automatic unlist in R h2o.importFile and h2o.uploadFile."
Revert "PUBEV-2953: Add automatic unlist in R h2o.importFile and h2o.uploadFile."

This reverts commit 1d2973f6207a3e5083853aa6be89bb20deb8a715.

mathemage/h2o-3,h2oai/h2o-3,jangorecki/h2o-3,mathemage/h2o-3,h2oai/h2o-dev,spennihana/h2o-3,h2oai/h2o-dev,jangorecki/h2o-3,michalkurka/h2o-3,h2oai/h2o-3,h2oai/h2o-3,h2oai/h2o-dev,spennihana/h2o-3,jangorecki/h2o-3,mathemage/h2o-3,h2oai/h2o-dev,michalkurka/h2o-3,h2oai/h2o-dev,spennihana/h2o-3,h2oai/h2o-3,h2oai/h2o-3,mathemage/h2o-3,mathemage/h2o-3,mathemage/h2o-3,jangorecki/h2o-3,h2oai/h2o-3,h2oai/h2o-dev,michalkurka/h2o-3,jangorecki/h2o-3,michalkurka/h2o-3,h2oai/h2o-3,jangorecki/h2o-3,jangorecki/h2o-3,michalkurka/h2o-3,michalkurka/h2o-3,mathemage/h2o-3,michalkurka/h2o-3,h2oai/h2o-dev,spennihana/h2o-3,spennihana/h2o-3,spennihana/h2o-3,h2oai/h2o-3,spennihana/h2o-3