fixes #12827
 After user migrates Harbor from v2.0.2, user got 404 when to pull specific images, and no work after push the same images again.

 Fix:
 1, If the issue is caused by missing repository data, this fix can revert the missing repository data and all things should be fine.
 2, If the issue is caused by missing blob data, this fix can revert the missing repository data and still left the media type of artifact
    as 'UNKNOWN', which leads the meta data and build history of the image cannot be shown in UI. User can delete and push the image again to
    resolve it.

Signed-off-by: wang yan <wangyan@vmware.com>