[hotplug ipv6] Add workaround for the test race

Sometimes with the cirros VM a race is seen with
ovs_create_tap feature https://launchpad.net/bugs/2069718
and ipv6 address is not configured, adding nic restart if
DAD failure is detected to workaround this.

Related-Bug: #2069718
Change-Id: Idbfa2c7150841f08ac6b63916dd559ba7f284a25
Signed-off-by: Yatin Karel <ykarel@redhat.com>
2 files changed