pudb crashes with escape character message when debugging via telnet.

I was working on a npyscreen app, and thought I would give pudb's remote debugging a try. The telnet prompt comes up, and when I connect via telnet from a separate console, I see the pudb screen. But if I press "n", the screen disappears and I get dumped onto a frozen telnet screen saying "Escape character is '^]'."

I don't know if I am doing something wrong, have some kind of terminal incompatibility (I'm running the standard Terminal in XFCE on Debian Stretch), or something else.

Movie attached that shows what it looks like. The triggering event is pressing "n" in pudb.

[debug_movie.zip](https://github.com/inducer/pudb/files/3310929/debug_movie.zip)