Using voltha-onos with ONOS 2.2.6 rc

Change-Id: If8fafb4d73fa2a307c36702f47eb125796c19578
diff --git a/releases/voltha-2.5 b/releases/voltha-2.5
index 906b7da..81e3954 100644
--- a/releases/voltha-2.5
+++ b/releases/voltha-2.5
@@ -18,4 +18,4 @@
 # kind-voltha's default which is 'master'.
 # Also we need to specify the tag for voltha/voltha-onos image since this is
 # not in the ONOS chart.
-export EXTRA_HELM_FLAGS="--set defaults.image_tag=null,images.onos.tag=voltha-2.5 "
+export EXTRA_HELM_FLAGS="--set defaults.image_tag=null,images.onos.tag=4.1.7 "