Currently an attempt to pull a reference which resolves to an OCI
artifact (Helm chart for example), results in a bit unrelated error
message `invalid rootfs in image configuration`.
This provides a more meaningful error in case a user attempts to
download a media type which isn't image related.
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
(cherry picked from commit 407e3a4552)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
f292bf0f4f