Annotation not found on PVCs is logged as ERROR

[mdnfiras]

k8s-snapshots logs an annotation not found entry for every PVC that doesn't have the annotation with a severity of ERROR, which produces so much noise.

I think that having some PVCs without the annotation should be okay, and at most logged as INFO.
This is already the case for PVs as you can see here: https://github.com/miracle2k/k8s-snapshots/blob/master/k8s_snapshots/core.py#L227

fix proposal here: #108