Update the voltha stack chart for latest openonu adapter chart version

Change-Id: I42389c433d4a2d2fad75fdc7e19109546f3be1e2
diff --git a/voltha-adapter-openonu/Chart.yaml b/voltha-adapter-openonu/Chart.yaml
index d6a69cd..22d119e 100644
--- a/voltha-adapter-openonu/Chart.yaml
+++ b/voltha-adapter-openonu/Chart.yaml
@@ -14,7 +14,7 @@
 ---
 apiVersion: "v1"
 name: "voltha-adapter-openonu"
-version: "2.7.10"
+version: "2.7.11"
 description: "A Helm chart for Voltha OpenONU Adapter"
 keywords:
   - "onf"