This doesn't really do anything, because libpurple without a backend doesn't do
any further signalling. But at least we'll get a contact with the option to
start a media session.
Testing Done:
Compiled and pressed the Audio/Video Call menu item.
Reviewed at https://reviews.imfreedom.org/r/1580/
# Biełaruski pierakład Pidgin
# Copyright (C) 2007 THE pidgin'S COPYRIGHT HOLDER
# This file is distributed under the same license as the pidgin package.