The anaconda-preexec script runs ahead of Anaconda to cache the IP
address of the network boot server in the /etc/hosts file, to avoid
further DNS queries during installation.
This update extends the checks to add support for IPv6 and to allow
for https network access.
Change-Id: Iadc86cbf971d6ecb0c478a2a16d5040d18a82ef0
Story: 2006980
Task: 38728
Signed-off-by: Don Penney <don.penney@windriver.com>