Previous we disabled some plugins that we want to keep around but can't port
yet by setting `build_by_default` to `false`. However, this isn't working on
many machines. I haven't figured out why, so instead lets just make their
meson.build files exit early.
Testing Done:
Ran the turtles on a machine that was still building these plugins.
Reviewed at https://reviews.imfreedom.org/r/3142/
# Biełaruski pierakład Pidgin
# Copyright (C) 2007 THE pidgin'S COPYRIGHT HOLDER
# This file is distributed under the same license as the pidgin package.