Delete and Verify VTEP TC failure : GENIUS CSIT

As Genius CSIT is enhanced to three switches, tunnels are randomly not getting deleted from tunnels-state datastore due to which delete and verify VTEP test case is failing

This happens only with 3 controller setup.

Failure Scenario : 8/53 failure cases.

Logs : https://logs.opendaylight.org/releng/vex-yul-odl-jenkins-1/builder-copy-sandbox-logs/573/Karthikagenius-csit-3node-gate-only-neon/25/