demande-import-test: use `wsgiref` instead of `telnetlib` for testing
The `telnetlib` module has been dropped in 3.13. The `wsgiref` module fit the
same purpose of being obscure and not imported yet.
#require serve
$ hg clone http://localhost:$HGPORT/ copy
abort: * (glob)
[100]
$ test -d copy
[1]
$ "$PYTHON" "$TESTDIR/dumbhttp.py" -p $HGPORT --pid dumb.pid
$ cat dumb.pid >> $DAEMON_PIDS
$ hg clone http://localhost:$HGPORT/foo copy2
abort: HTTP Error 404: * (glob)
[100]
$ killdaemons.py