VPN: vpn suite fails for all jobs of rocky when compute and controller are same VM.

Same testcase works of controller and compute are separate for rocky

and same testcase for works for all combinations of controller and compute in case of queens.

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Logs:

https://logs.opendaylight.org/releng/vex-yul-odl-jenkins-1/netvirt-csit-1node-1cmb-0ctl-0cmp-openstack-rocky-upstream-stateful-neon/46/robot-plugin/log_full.html.gz

https://jenkins.opendaylight.org/releng/view/netvirt-csit/job/netvirt-csit-1node-1cmb-0ctl-0cmp-openstack-rocky-upstream-stateful-itm-direct-tunnels-sodium/

https://jenkins.opendaylight.org/releng/view/netvirt-csit/job/netvirt-csit-1node-1cmb-0ctl-0cmp-openstack-rocky-upstream-stateful-neon/