virNetClientStreamQueuePacket: Set st->incomingEOF on the end of stream
    
    While reworking client side of streams, I had to postpone payload
    decoding so that stream holes and stream data can be
    distinguished in virNetClientStreamRecvPacket. That's merely what
    18944b7aea46d does. However, I accidentally removed one important
    bit: when server sends us an empty STREAM packet (with no
    payload) - meaning end of stream - st->incomingEOF flag needs to
    be set. It used to be before I touched the code. After I removed
    it, virNetClientStreamRecvPacket will try to fetch more data from
    the stream, but it will never come.
    
    Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
    Reviewed-by: Jim Fehlig <jfehlig@suse.com>