message: update default autorest.nodejs version to 1.9.4
diff: @@ -41,7 +41,7 @@ use-extension:
  ``` yaml $(nodejs)
  use-extension:
  - "@microsoft.azure/autorest.nodejs": "1.9.3"
  + "@microsoft.azure/autorest.nodejs": "1.9.4"
  ```
  ``` yaml $(php)
  