Cancelling a transfer when the network connection is down fails to error out deal

[dirkmc]

When the user cancels a transfer, it should also cancel the deal, even if the network connection is down.

In practice this does not appear to work. This deal was stuck in StorageDealTransferring:

$ lotus client list-transfers --show-failed| grep b5u
1516  Failed              ...ZGZVb4n8  ...hxjqfjqe  Y           3.317GiB     ...powhddwso2egkkuxariixvqvtpqbgtvb5u"}}  

$ lotus client cancel-transfer 1516
ERROR: unable to send cancel to channel FSM: %!w(<nil>)

$ lotus client list-transfers --show-failed| grep b5u
1516  Failed              ...ZGZVb4n8  ...hxjqfjqe  Y           3.317GiB     ...powhddwso2egkkuxariixvqvtpqbgtvb5u"}}  

$ lotus client list-deals | grep b5u
...qbgtvb5u  0        f022352   StorageDealClientTransferRestart  N                 N         ...wto77qaa  7.938 GiB  0.0004172624 FIL          521578    false

[dirkmc]

Fixed by #5032