Forcing jenkins not to kill pipeline child program. Avoiding fast disconnectiong/reconnection of agg switch that was yielding unconsistent goup state

Change-Id: If377fe02c5faeb89ad83797fa63dc3bbc8c57c8b
diff --git a/Jenkinsfile-voltha-bal31-build b/Jenkinsfile-voltha-bal31-build
index cac600e..9e6653e 100644
--- a/Jenkinsfile-voltha-bal31-build
+++ b/Jenkinsfile-voltha-bal31-build
@@ -105,7 +105,7 @@
                         export KUBECONFIG=$WORKSPACE/${configBaseDir}/${configKubernetesDir}/${configFileName}.conf
                         #This uses the default route out, porperly configured is the management
                         mgmt_address=`ip route get 1 | awk '{print \$NF;exit}'`
-                        bash -c "while true; do kubectl port-forward -n default service/onos-openflow --address=\$mgmt_address 6653:6653; done" >> /dev/null 2>&1 &
+                        JENKINS_NODE_COOKIE=dontkill kubectl port-forward -n default service/onos-openflow --address=\$mgmt_address 6653:6653 >> /dev/null 2>&1 &
                         """
                     }
                 }