Revert mis-merged reverts of vendor.conf

PR #440 reverted the vendor.conf edits of #426.  This passed CI
because the corresponding vendor/* subpackages were not modified.

Restore the vendor.conf changes, and re-run full (vndr) to ensure
the two are consistent again.

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

vendor/github.com/containers/storage/store.go

@@ -1888,10 +1888,16 @@ func (s *store) layersByMappedDigest(m func(ROLayerStore, digest.Digest) ([]Laye
 		}
 		storeLayers, err := m(store, d)
 		if err != nil {
-			return nil, err
+			if errors.Cause(err) != ErrLayerUnknown {
+				return nil, err
+			}
+			continue
 		}
 		layers = append(layers, storeLayers...)
 	}
+	if len(layers) == 0 {
+		return nil, ErrLayerUnknown
+	}
 	return layers, nil
 }