[PATCH 2/3] doveadm: compress-connect - Don't hang when server rejects COMPRESS

[PATCH 2/3] doveadm: compress-connect - Don't hang when server rejects COMPRESS

After sending a COMPRESS command the client stopped reading stdin and
waited for the server's reply, but it only resumed on an "OK Begin
compression" reply. If the server rejected COMPRESS (e.g. a NO reply for
an unsupported mechanism), compress_waiting was never cleared: the client
waited forever for an OK that never came while the server waited for the
next command, deadlocking the session.

Remember the COMPRESS command tag and treat any tagged reply to it that
isn't the compression-start reply as a rejection, resuming the pipelined
input.

Gbp-Pq: Name 0002-doveadm-compress-connect-Don-t-hang-when-server-reje.patch