Update import logic

Signed-off-by: Derek McGowan <derek@mcg.dev>

images/archive/reference.go

@@ -41,6 +41,9 @@ func AddRefPrefix(image string) func(string) string {
 // a full reference.
 func refTranslator(image string, checkPrefix bool) func(string) string {
 	return func(ref string) string {
+		if image == "" {
+			return ""
+		}
 		// Check if ref is full reference
 		if strings.ContainsAny(ref, "/:@") {
 			// If not prefixed, don't include image