Fix for github issue 34. The parsing logic is changed.

[msenmurugan]

The different error messages will get printed based on the existing code. See for sample code in image_annotator.go

_, imageSha, err := docker.ParseImageIDString(osImage.DockerImageReference)
if err != nil {
   metrics.RecordError("image_annotator", "unable to parse openshift imageID")
   log.Errorf("unable to parse openshift imageID from image %s: %v", imageName, err)
   continue
}