For multinode setup, a couple of updates to /etc/nova/nova.conf was
needed for live migration.
serial_console needed to be disabled and vncserver_listen needed to
be set to any for the vncserver to accept connections from all of the
compute nodes.
Change-Id: I62ebc2a07ca525bd80da130981f337806b2b89ae
Closes-Bug: #1649638