guestbook-go: update redis master image

This now matches the image used in the guestbook (non-go) example.

Workaround for containerd/containerd#4756

Author: justinsb

guestbook-go/redis-master-controller.json

@@ -25,7 +25,7 @@
             "containers":[
                {
                   "name":"redis-master",
-                  "image":"redis:2.8.23",
+                  "image":"k8s.gcr.io/redis:e2e",
                   "ports":[
                      {
                         "name":"redis-server",