neutron-tempest-plugin single node scenario jobs were switched to use L3HA routers by default in [1] and this patch reflects that change in our docs. [1] https://review.opendev.org/721805 Depends-On: https://review.opendev.org/721805 Change-Id: Ib3c6be059dc4f3e62a9c5d25588d44ed4a3df971