Pin Helm version to v2.14.3

Change-Id: I5df8563178a1b67cf943761f6f96396f38f3c499
diff --git a/jjb/pipeline/voltha-go-tests.groovy b/jjb/pipeline/voltha-go-tests.groovy
index ed22ee3..8d282c5 100644
--- a/jjb/pipeline/voltha-go-tests.groovy
+++ b/jjb/pipeline/voltha-go-tests.groovy
@@ -40,6 +40,7 @@
       steps {
         sh """
            cd kind-voltha/
+           export DESIRED_VERSION=v2.14.3    # For Helm
            EXTRA_HELM_FLAGS="${params.extraHelmFlags}" VOLTHA_LOG_LEVEL=DEBUG TYPE=minimal WITH_RADIUS=y WITH_BBSIM=y INSTALL_ONOS_APPS=y CONFIG_SADIS=y WITH_SIM_ADAPTERS=n FANCY=0 ./voltha up
            """
       }