Outstanding calls are not rejected on disconnects #315
Description
Reported via matrix: the connection shutdown logic does not currently reject all promises in the questions table. call messages that are still in the send queue when the connection drops are handled correctly, but call messages which are already on the wire are never rejected.
Fixing this should be relatively straightforward; we need to walk over the questions table and reject everything. The only hitch is to make sure we don't double-free things that are in the queue.