Fix crash on inspecting an OCI image with no config
Fix crash on inspecting an OCI image with no config

Don't use the schema2 config field, which is a pointer that
may be nil; the OCI config is an embedded struct and accessing it
is always possible.

Using the OCI config is more correct anyway.

Signed-off-by: Miloslav Trmač <9c008e38982a5397deb855345fb164f0558459ae@redhat.com>

containers/image,containers/image