This patch contains a workaround for one of extra dhcp opts test,
test_extra_dhcp_opts_disabled_enabled_dhcp4, that uses a strict
regex for getting domain_name between 'search' and eand of the line.
In some cases the test is failing because of an extra entry 'n'
before the end of the line. This still should be investigated.
Meanwhile we apply a workaround in order to unblock the gates.
The workaround makes the regex less strict and still checks for
a proper value of the domain_name.
This patch also handles 2 comments from the previous patch.
Change-Id: Icb65bd5aefab7d23b93f148502667c8c4e62bdc2
56c7eb3b50