message: Fix: software wallet keystore getter prop
  It now has to use the `privateKey` getter to get the value,
  since it's not directly assigned to the prop anymore.
  It was refactored into a getter in
diff: @@ -120,7 +120,13 @@ export default class SoftwareWallet {
  }
  get keystore(): Promise<string | void> {
  + /*
  + * We're wrapping the getter (returning actually) in a IIFE so we can
  + * write it using a `async` pattern.
  + */
  + return (async () => {
  if (internalEncryptionPassword) {
  + const privateKey: string = await this.privateKey;
  /*
  * Memoizing the getter
  *
  @@ -139,11 +145,12 @@ export default class SoftwareWallet {
  * the keystore JSON string
  *
  * @TODO Validate the password
  + *
  * The password won't work if it's not a string, so it will be best if
  * we write a string validator for it
  */
  secretStorage.encrypt(
  - this.privateKey,
  + privateKey,
  internalEncryptionPassword.toString(),
  ),
  }),
  @@ -155,17 +162,19 @@ export default class SoftwareWallet {
  * the keystore JSON string
  *
  * @TODO Validate the password
  + *
  * The password won't work if it's not a string, so it will be best if
  * we write a string validator for it
  */
  secretStorage.encrypt(
  - this.privateKey,
  + privateKey,
  internalEncryptionPassword.toString(),
  )
  );
  }
  warning(messages.noPassword);
  return Promise.reject();
  + })();
  }
  /*
  