WSJ English routes null properties

### Routes

```routes
/wsj/:lang/:category?
```

### Full routes

```fullroutes
/wsj/en-us/us
/wsj/en-us/world
/wsj/en-us/politics
/wsj/en-us/economy
/wsj/en-us/business
/wsj/en-us/technology
/wsj/en-us/markets
/wsj/en-us/books-arts
/wsj/en-us/realestate
/wsj/en-us/life-work
/wsj/en-us/style-entertainment
/wsj/en-us/sports
```

### Related documentation

https://docs.rsshub.app/routes/traditional-media#the-wall-street-journal-(wsj)-hua-er-jie-ri-bao

### What is expected?

Return XML file for RSS feed

### What is actually happening?

Error message: null properties

### Deployment information

RSSHub demo (https://rsshub.app)

### Deployment information (for self-hosted)

_No response_

### Additional info

```shell
Route requested: /en-us/us

Error message: Cannot read properties of null (reading '0')

Helpful Information to provide when opening issue:
Path: /en-us/us
Node version: v18.17.1
Git Hash: eebd99c
```

### This is not a duplicated issue

- [X] I have searched [existing issues](https://github.com/DIYgod/RSSHub/issues) to ensure this bug has not already been reported