Don't register polkit agent if we cannot connect to system bus
Don't register polkit agent if we cannot connect to system bus

This works around an old polkit client library bug which would cause
a segfault in this situation. The bug was fixed long ago in upstream
polkit, but is still present in Debian 10 'buster', Ubuntu 19.04 'disco'
and all older releases, due to Debian/Ubuntu using a branch of polkit
to avoid the mozjs dependency. It should finally get fixed in Debian 11
and Ubuntu 19.10.

Signed-off-by: Simon McVittie <smcv@collabora.com>
Bug-Debian: https://bugs.debian.org/923046

Closes: #2997
Approved by: matthiasclasen

matthiasclasen/flatpak,flatpak/flatpak,matthiasclasen/flatpak,flatpak/flatpak,flatpak/flatpak,matthiasclasen/flatpak,matthiasclasen/flatpak,matthiasclasen/flatpak,flatpak/flatpak,flatpak/flatpak