fix nmstate DS api version
Our monitoring code only watches DS from api group apps/v1,
not (out-dated) extensions/v1beta1.
---
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
kind: DaemonSet
metadata:
name: nm-state-controller
namespace: nmstate
spec:
+ selector:
+ matchLabels:
+ name: nm-state-controller
template:
metadata:
labels:
+ name: nm-state-controller
nmstate.io: state-controller
spec:
serviceAccountName: nmstate-state-controller
