Even when a custom nameserver is set by the caller they may wish to
still keep the original nameserver too. This is needed by podman/buildah
when they only want to add the slirp4netns dns ip at the beginning for
example.
Signed-off-by: Paul Holzinger <pholzing@redhat.com>
both buildah and podman currently use a slightly different resolvconf lib,
to prevent duplication and having to fix bugs twice they should both use
this new package instead.
Signed-off-by: Paul Holzinger <pholzing@redhat.com>