message: fix clippy complains about .unwrap()
diff: @@ -132,18 +132,17 @@ fn derive_extended_secret_key_from_mnemonic(
  ) -> Result<ExtendedSecretKey, SignerError> {
  let lang = Language::from_language_code(language_code);
  - if lang.is_none() {
  - return Err(SignerError::GenericString(
  - "Unknown language code".to_string(),
  - ));
  - };
  -
  - let mnemonic = bip39::Mnemonic::from_phrase(&mnemonic, lang.unwrap())
  + match lang {
  + Some(l) => {
  + let mnemonic = bip39::Mnemonic::from_phrase(&mnemonic, l)
  .map_err(|err| SignerError::GenericString(err.to_string()))?;
  let seed = Seed::new(&mnemonic, password);
  derive_extended_secret_key(seed.as_bytes(), path)
  + },
  + None => Err(SignerError::GenericString("Unknown language code".to_string()))
  + }
  }
  /// Returns a public key, private key and address given a mnemonic, derivation path and a password
  