wrong client-go version in go.mod

[pulish]

Now:
k8s.io/client-go v1.19.0
Should be:
k8s.io/client-go v0.19.0

Error message:
go: github.com/kubernetes-csi/csi-lib-utils@v0.8.0 requires
k8s.io/client-go@v1.19.0: reading k8s.io/client-go/go.mod at revision v1.19.0: unknown revision v1.19.0