add networking.k8s.io for ingress (#8091)

* add networking.k8s.io for ingress

level=error ts=2020-10-19T08:32:30.544Z caller=klog.go:96 component=k8s_client_runtime func=ErrorDepth msg="github.com/prometheus/prometheus/discovery/kubernetes/kubernetes.go:494: Failed to watch *v1beta1.Ingress: failed to list *v1beta1.Ingress: ingresses.networking.k8s.io is forbidden: User \"system:serviceaccount:monitoring:prometheus\" cannot list resource \"ingresses\" in API group \"networking.k8s.io\" at the cluster scope"

Signed-off-by: root <likerj@inspur.com>

* Update rbac-setup.yml

Signed-off-by: root <likerj@inspur.com>

documentation/examples/rbac-setup.yml

@@ -20,6 +20,7 @@ rules:
   verbs: ["get", "list", "watch"]
 - apiGroups:
   - extensions
+  - networking.k8s.io
   resources:
   - ingresses
   verbs: ["get", "list", "watch"]