Refer to *current-message*, not *current-words*.

This allows me to "enter" irc-process-line.rkt without error:

    racket@> ,enter "/Users/erichanchrow/git-repositories/Me/rudybot/irc-process-line.rkt"
    irc-process-line.rkt:870:20: *current-message*: unbound identifier in module
      in: *current-message*