Disable LightDM custom configuration.

Disable LightDM custom configuration temporarily, to prevent #762211 from
happening. For more details, see
<https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=762211> ("lightdm
crashes on startup, system falls back to console").

Signed-off-by: Ville Korhonen <ville.korhonen@ylioppilastutkinto.fi>
Removed existence check for dpkg-parsechangelog.

If-clause causes problems when trying to import variables into chroot.

Signed-off-by: Ville Korhonen <ville.korhonen@ylioppilastutkinto.fi>
Merge branch 'master' into fix/lightdm-breaks-debbug-762211

* master:
  Removed existence check for dpkg-parsechangelog.
  Add link to configuration instructions.
  Add initial rules for Jenkins console output parsing.
Use environment variables from digabi.local.
Revert "Disable LightDM custom configuration."

This reverts commit bdbdf8a288aef929deaf6f7af75d5b2ccf29ef06.
Disable LightDM configuration temporarily.