message: Update vault.rs
  Closes:
diff: @@ -341,7 +341,7 @@ fn test_vault_crypto_policies() {
  assert_ne!(rotater_store.rotate_key(CRYPTO_KEY).unwrap(), pubkey);
  rotater_store.sign(CRYPTO_KEY, &message).unwrap_err();
  // Verify a rotater with another namespace has no permission for the operations
  - let rotater_store_with_namespace = VaultStorage::new(
  + let mut rotater_store_with_namespace = VaultStorage::new(
  dev::test_host(),
  rotater_token,
  Some(VAULT_NAMESPACE_1.into()),
  @@ -350,7 +350,7 @@ fn test_vault_crypto_policies() {
  true,
  );
  rotater_store_with_namespace
  - .get_public_key(CRYPTO_KEY)
  + .rotate_key(CRYPTO_KEY)
  .unwrap_err();
  let new_pubkey = storage.get_public_key(CRYPTO_KEY).unwrap().public_key;
  