When you run ovs-sandbox, it finishes with a note describing the dummy
environment it has set up. Add some additional text that indicates that
OVN is also enabled when that is the case.
Signed-off-by: Russell Bryant <russell@ovn.org> Acked-by: Ben Pfaff <blp@ovn.org> Acked-by: Ryan Moats <rmoats@us.ibm.com>