i3wm: doesn't start (tested on qemu)

!52 (merged) changes all X11 DEs to use lightdm. i3wm used to use lxdm before, but to make it consistent i3 also uses lightdm now.

While testing that MR I've noticed that I can't start i3 in Qemu. And also that it does not work without the MR, so it's not a regression from there.

Does i3 still work with fresh installations on the n900? Would somebody like to investigate why it does not work in qemu (look at the logs with logread), or does it work for others?