[VOL-3690] Using openonu-adapter-go as default

Change-Id: I40304b662384734ca30568071c1ab5a442df6453
diff --git a/releases/voltha-2.3.0-rc1 b/releases/voltha-2.3.0-rc1
index a6f08c4..d892ab6 100644
--- a/releases/voltha-2.3.0-rc1
+++ b/releases/voltha-2.3.0-rc1
@@ -7,3 +7,5 @@
 export VOLTHA_ADAPTER_OPEN_OLT_CHART_VERSION=2.2.2
 export VOLTHA_ADAPTER_OPEN_ONU_CHART_VERSION=2.2.2
 export ONOS_CHART_VERSION=1.1.4
+
+export EXTRA_HELM_FLAGS="--set use_openonu_adapter_go=false "