message: add default instance for derivation scheme
diff: @@ -77,6 +77,9 @@ pub enum DerivationScheme {
  V1,
  V2,
  }
  +impl Default for DerivationScheme {
  + fn default() -> Self { DerivationScheme::V2 }
  +}
  /// Seed used to generate the root private key of the HDWallet.
  ///
  