Bug#835883: gjs: please use dbus-daemon directly in tests

[Simon McVittie]

Source: gjs
Version: 1.45.4-1
Severity: normal
Tags: upstream
User: dbus at packages.debian.org
Usertags: dbus-launch dbus-launch-for-tests

As described in <https://lists.debian.org/debian-devel/2016/08/msg00554.html>
I'm trying to reduce how much dbus-launch is used in Debian.
This package currently uses dbus-launch in a test script.

This Flatpak commit illustrates how eval `dbus-launch` can be replaced
by invoking dbus-daemon directly, avoiding the X11-specific dbus-launch:
https://github.com/flatpak/flatpak/commit/6cc8062cfb3f9410d54a27e7ccca77c103e441e8

Alternatively, if run-with-dbus --system (a fake system bus) is not
actively used, it can be replaced with something like this:

    dbus-run-session -- some-test

Thanks,
    S