Better fix for openstack cinder zone issue using ignore-volume-az option (#2980)

* Better fix for openstack cinder zone issue[1][2]
using ignore-volume-az option[3].
[1]: https://github.com/kubernetes-incubator/kubespray/pull/2155
[2]: https://github.com/kubernetes-incubator/kubespray/pull/2346
[3]: https://github.com/kubernetes/kubernetes/pull/53523

* Remove kube-scheduler-policy.yaml