Revert "Return empty binary if there's no data to receive."

This reverts commit 3dde33468e660872d062f35a87259d7a46faef3f.

Change-Id: Ia1ec7e303ddf22dd73c5d255d0ca7a0a1e7b338c
Reviewed-on: http://review.couchbase.org/34176
Reviewed-by: Sarath Lakshman <sarath@couchbase.com>
Tested-by: Volker Mische <volker.mische@gmail.com>