Default DIB image now results in ubuntu xenial which does not work for dhcp-all-interfaces.

[Julia Kreger]

The default dib image built with ubuntu results in dhcp-all-interfaces putting invalid config in place which results in a non-functional IPA image.

Thanks go to Yolanda for finding this issue. Seems the fix is to be to offer scripts for ubuntu systemd based deployments as there is no ifup in ubuntu denial.

https://git.openstack.org/cgit/openstack/diskimage-builder/tree/elements/dhcp-all-interfaces/install.d/50-dhcp-all-interfaces?id=587d14feed3cfdc6df9bf2d31898d5c81a377710#n25

<yolanda> Date: Wed Nov 2 16:05:10 2016 +0000
<yolanda> Merge "Make xenial the ubuntu default"
<yolanda> commit bc66298937c55321874eb599aeddde25ce125dd3

[Andrey Shestakov (ashestakov)]

Bug in dib https://bugs.launchpad.net/diskimage-builder/+bug/1647853