EOF issues with sunset's channels

[brainstorm]

Potentially fixes issue #22 ?

I have not tested it in hardware (yet, therefore draft PR status), but I have been wondering for a while if I could fix the client connection getting stuck after the server closes (or dies).

In other words, when I'm testing with zssh@<local_ip>, the client cannot exit the session unless I kill it via this shell script:

#!/usr/bin/env sh
kill `ps aux | grep zssh | grep -v grep | awk '{ print $2 }'`

Or use the hidden SSH menu to kill the frozen session.