Comment 2 for bug 1758000

Reviewed: https://review.openstack.org/556556
Committed: https://git.openstack.org/cgit/openstack/diskimage-builder/commit/?id=301eac8e8b12e321a7046c5fc7739bde56b6b385
Submitter: Zuul
Branch: master

commit 301eac8e8b12e321a7046c5fc7739bde56b6b385
Author: Clark Boylan <email address hidden>
Date: Mon Mar 26 08:22:52 2018 -0700

    Fix element-provides in debian element

    The debian element depends on debian-minimal now which provides
    operating-system. This means that the debian element can no longer
    provide operating-system and doing so results in an error when using the
    debian element.

    The fix is simple just rely on the fact that debian-minimal provides
    operating-system and remove this element-provides from debian.

    Fixes-Bug: 1758000
    Change-Id: I524feeb82c19046ec987eb1186c7f4568309e559