The code 46 handler parsed the filename and only logged it, so a queued
download whose peer reported an upload failure never received
DownloadStatus::Failed and hung until the caller's own timeout.
The handler now sends PeerMessage::UploadFailed through the dispatcher
and the actor stamps the peer's username on it before forwarding
ClientOperation::UploadFailed into the existing failure path. The
variant's username field stays for API compatibility; the wire message
cannot name anyone but the connected peer, so the actor supplies it.
Fixes#30
Michel de Graaf
d30ca757bc