Use openonu-py adapter chart version 2.4.3 for voltha-2.4 release

Change-Id: Ic2c3907bf038a596a1e630407961919ca069eefc
diff --git a/VERSION b/VERSION
index cdb98d2..4de34c3 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-5.1.3
+5.1.4-dev