Remove unnecessary includes

Change-Id: Ib1a90a07b2d467a81927c53917e05a1af6ba4ee6
Reviewed-on: https://code.wireshark.org/review/3666
Petri-Dish: Michael Mann <mmann78@netscape.net>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Michael Mann <mmann78@netscape.net>