Update plugin image version in readme example cofiguration.

Signed-off-by: Ashutosh Narkar <anarkar4387@gmail.com>

README.md

@@ -104,7 +104,7 @@ To deploy OPA-Istio include the following container in your Kubernetes Deploymen
 
 ```yaml
 containers:
-- image: openpolicyagent/opa:0.10.7-istio
+- image: openpolicyagent/opa:0.10.7-istio-2
   imagePullPolicy: IfNotPresent
   name: opa-istio
   volumeMounts:
@@ -273,4 +273,4 @@ repository. You will need to have Glide v0.13 or newer installed.
 
 If you update any of the gRPC, protobuf, or
 `github.com/envoyproxy/data-plane-api` dependencies, you should regenerate
-the Go code that depends on them by running `gen-protos.sh` in this directory.
+the Go code that depends on them by running `gen-protos.sh` in this directory.