Comment 4 for bug 1392564

Reviewed: https://review.openstack.org/137238
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=8b5c08b35e75de6e09b75ed01120b6fdedb9125f
Submitter: Jenkins
Branch: stable/juno

commit 8b5c08b35e75de6e09b75ed01120b6fdedb9125f
Author: Xu Han Peng <email address hidden>
Date: Fri Nov 14 10:53:59 2014 +0800

    Fix metadata proxy start problem for v6-v4 network

    Commit 1b66e11b5d8c0b3de0610ca02c3e10b6f64ae375 introduces
    a new problem that metadata proxy will not be started when
    an isolated network contains ipv6 subnet with dhcp enabled
    and a ipv4 subnet.

    This fix separates the checks to enable dhcp and enable metadata
    so metadata proxy can be started if there is ipv4 subnet exists
    in the network with metadata enabled.

    Change-Id: If26806083db225e9ab30d75fa6c728ce99a7cafe
    Closes-Bug: 1392564
    (cherry picked from commit 4c128c351589ef9f2fc1e084c655a97bdbbda7ce)