This should make the process more robust, in combination with setting the
timeout to G_MAXINT, rather than -1, which effectively defaults to 25
seconds. Otherwise, it is possible for the session manager to be
unresponsive, perhaps waiting for a synchronous call of its own to time out,
and then the session manager will eventually process the RegisterClient, but
at-spi-bus-launcher will have timed out, meaning that we successfully register
with the session manager but don't ever set up our signal handler, meaning
that, later, the session manager sends a QueryEndSession to us, but we don't
see it.

https://bugzilla.opensuse.org/show_bug.cgi?id=1154582