set readinessProbe to https

Fix the error
Readiness probe failed: Get "http://100.105.5.5:5556/healthz": dial tcp 100.105.5.5:5556: connect: connection refused
Client sent an HTTP request to an HTTPS server.

examples/k8s/dex.yaml

@@ -53,6 +53,7 @@ spec:
           httpGet:
             path: /healthz
             port: 5556
+            scheme: HTTPS
       volumes:
       - name: config
         configMap: