Remove obsolete dissectors.

Change-Id: Icd480491670de9d8495a95861b18a8a5cb9724b4
Reviewed-on: https://code.wireshark.org/review/4006
Petri-Dish: Anders Broman <a.broman58@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Anders Broman <a.broman58@gmail.com>