SEBA-564 Use Mininet image with OvS 2.9.0 for QinQ matching

Change-Id: I75e710747ebfc9d91a6352ce9999770ffd74d4eb
diff --git a/mininet/Chart.yaml b/mininet/Chart.yaml
index ba62bad..39568c7 100644
--- a/mininet/Chart.yaml
+++ b/mininet/Chart.yaml
@@ -17,4 +17,4 @@
 appVersion: "1.0"
 description: A Helm chart for Mininet
 name: mininet
-version: 0.2.0
+version: 0.3.0