binding voltctl version to 2.3 release

Change-Id: I2ce6507bbc71dcb5ec068266ac29055d89b21111
diff --git a/releases/voltha-2.3 b/releases/voltha-2.3
index d8646ec..ac40918 100644
--- a/releases/voltha-2.3
+++ b/releases/voltha-2.3
@@ -8,6 +8,7 @@
 export VOLTHA_ADAPTER_OPEN_OLT_CHART_VERSION=2.3.2
 export VOLTHA_ADAPTER_OPEN_ONU_CHART_VERSION=2.3.0
 export ONOS_CHART_VERSION=3.0.1
+export VOLTCTL_VERSION=1.0.18
 export WITH_ONOS=legacy
 
 # defaults.image_tag=null will use the image tags in the Helm charts rather than