sandbox: disable ssl for backup ovn southbound db

sandbox: disable ssl for backup ovn southbound db

Since the sandbox environment was changed to enable SSL usage for
OVN_Southbound connections, the backup southbound server emits
the log message "socket_util|ERR|6642: bind: Address already in use"
every 2.5 seconds.

Fix by configuring the backup db server to not use remote configuration
from the database (the unix: socket can still be used, as was the
case before SSL was enabled).

Fixes: 0ced2a5c5e47 ("sandbox: use ssl for ovn-controller to sb db connection")
Signed-off-by: Lance Richardson <lrichard@redhat.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>