Switch to official quay.io repo for nginx image (#876)

Signed-off-by: Jonathan West <[email protected]>

Author: jgwest

test/examples/nginx/nginx.yaml

@@ -14,6 +14,6 @@ spec:
     spec:
       containers:
       - name: nginx
-        image: nginxinc/nginx-unprivileged
+        image: quay.io/nginx/nginx-unprivileged
         ports:
         - containerPort: 80