Fix formatting of /etc/issue \w different ip sizes

Pointed out by Artem Panchenko that if the ip sizes
are different it will result in ugly formatting.

This is follow up of bug #1351937 and previous patch
https://review.openstack.org/#/c/113605/

Change-Id: I08ce905f8386fe121c8dc9c4963601b674fccf61
Merge "Fix formatting of /etc/issue \w different ip sizes"