daemon: fix wrong request count for sparse stream

daemon: fix wrong request count for sparse stream

Similar to when actual data is being written to the stream, it is
necessary to acknowledge handling of the client request when a hole is
encountered. This is done later in daemonStreamHandleWrite by sending a
fake zero-length reply if the status variable is set to
VIR_STREAM_CONTINUE. It seems that setting status from the message
header was missed for holes in the introduction of the sparse stream
feature.

Signed-off-by: Vincent Vanlaer <libvirt-e6954efa@volkihar.be>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>