Bug#857995: respawn loop due to insufficient permissions

[Jeremy Bicha]

By the way, the constant respawn is really annoying when I install
stretch on VirtualBox.

I use the latest stretch testing netboot iso to install. Then I need
to boot to a command line with Internet so I can install
virtualbox-guest-x11 from sid (in order to be able to use a graphical
desktop because Debian Security doesn't want VirtualBox in stretch).
But first I have to wait 5 minutes for gdm to stop trying to load
(effectively a Denial of Service) before I can use a virtual terminal.

Thanks,
Jeremy Bicha