Add fallbacks for token name if OriginalName unset

Will use Name if it is available, and otherwise will use UniqueID, which
is not descriptive but should always be available.

Should fix one of the complaints reported in #1.

cmd/authy-export/authy-export.go

@@ -70,7 +70,7 @@ func main() {
 	for _, tok := range tokensResponse.AuthenticatorTokens {
 		decrypted, err := tok.Decrypt(string(pp))
 		if err != nil {
-			log.Printf("Failed to decrypt token %s: %v", tok.OriginalName, err)
+			log.Printf("Failed to decrypt token %s: %v", tok.Description(), err)
 			continue
 		}
 
@@ -80,7 +80,7 @@ func main() {
 		u := url.URL{
 			Scheme:   "otpauth",
 			Host:     "totp",
-			Path:     tok.OriginalName,
+			Path:     tok.Description(),
 			RawQuery: params.Encode(),
 		}
 		fmt.Println(u.String())

objects.go

@@ -182,3 +182,15 @@ func (t AuthenticatorToken) Decrypt(passphrase string) (string, error) {
 	}
 	return strings.ToUpper(string(buf)), nil
 }
+
+// Description returns OriginalName if not empty, otherwise Name,
+// otherwise `Token-{UniqueID}`.
+func (t AuthenticatorToken) Description() string {
+	if t.OriginalName != "" {
+		return t.OriginalName
+	}
+	if t.Name != "" {
+		return t.Name
+	}
+	return "Token-" + t.UniqueID
+}