Backported from X.org:

 commit ce6546337487c052b5dd3c04d3d8d4b09d691c3d
 Author: Keith Packard <keithp@keithp.com>
 Date:   Tue May 31 09:38:17 2016 -0700

    os: Initialize NotifyFds earlier in startup

    If the server calls AbortServer during the first-time initialization
    (which can happen if you start the server on an already using
    DISPLAY), then the dbus code will shut down and call the notify fd
    interface. If the notify fd list hasn't been initialized, the server
    will crash.
Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Backported-to-NX-by: Mike Gabriel <mike.gabriel@das-netzwerkteam.de>