Leave /etc/init/docker.conf untouched; use /etc/default/docker instead.

The [documentation](http://docs.docker.io/en/latest/use/host_integration/) tells everyone to influence Docker's launch behaviour by editing `/etc/default/docker`. Your module replaces `etc/init/docker.conf`with a custom version which ignores `/etc/default/docker`. 
