message: Fix: `purser-software` open a wallet using keystore
diff: import { Wallet as EthersWallet } from 'ethers/wallet';
  import { isValidMnemonic, fromMnemonic } from 'ethers/utils/hdnode';
  +import { isSecretStorageWallet } from 'ethers/utils/json-wallet';
  import {
  derivationPathSerializer,
  @@ -82,7 +83,7 @@ export const open = async (
  /*
  * @TODO Detect if existing but not valid keystore, and warn the user
  */
  - if (keystore && EthersWallet.isEncryptedWallet(keystore) && password) {
  + if (keystore && isSecretStorageWallet(keystore) && password) {
  const keystoreWallet: Object =
  /*
  * Prettier suggests changes that would always result in eslint
  @@ -90,7 +91,7 @@ export const open = async (
  *
  * Nevertheless, by inserting this comment, it works :)
  */
  - await EthersWallet.fromEncryptedWallet(keystore, password);
  + await EthersWallet.fromEncryptedJson(keystore, password);
  /*
  * Set the keystore and password props on the instance object.
  *
  