request back from the receive queue -- it might already be processed
by remote_recv_thread, which lead to crashes like below:
(primary) Unable to receive reply header: Connection reset by peer.
(primary) Unable to send request (Connection reset by peer):
WRITE(954662912, 131072).
(primary) Disconnected from kopusha:7772.
(primary) Increasing localcnt to 1.
(primary) Assertion failed: (old > 0), function refcnt_release,
file refcnt.h, line 62.
Taking the request back was not necessary (it would properly be
processed by the remote_recv_thread) and only complicated things.
MFC after: 2 weeks