fix: don't throw if it's not a proper old-style link
fix: don't throw if it's not a proper old-style link

We are still supporting old style links, i.e. JSON where `/` as key
signals a link. Though the JSON could could also contain such a key
without having a CID as value. Instead of throwing an error, treat it
as not being a link.

ipld/js-ipld-resolver