Patch for /trunk/ConciseArgs.hpp

```
Fixed spelling on unknown on line 142
```

Original issue reported on code.google.com by `aba...@gmail.com` on 18 Oct 2013 at 1:46

Attachments:
- [ConciseArgs.hpp.patch](https://storage.googleapis.com/google-code-attachments/concise-args/issue-1/comment-0/ConciseArgs.hpp.patch)
