Fix indentation

Signed-off-by: Arnaud Porterie <arnaud.porterie@docker.com>
Merge pull request #9802 from icecrime/9284_tianon_ocd

Fix indentation
Adjust Dockerfile style to be more consistent

Signed-off-by: Andrew "Tianon" Page <admwiggin@gmail.com>
Merge pull request #9804 from tianon/dockerfile-tweaks

Adjust Dockerfile style to be more consistent