setStaticDir and regex-based routing don't work as expected
When I use "static" I get 404 errors and when I use "./static" I get 400 "Bad Request" instead.

```nim
settings:
  staticDir = "./static" # "static" doesn't help either
```

I also tried regex-based routing:

```nim
  get re"^\/static\/.*\.css$":
    writeFile("t.log", request.matches[0])
    resp readFile(request.matches[0])
```

The route will match but the file will be empty, even if I replace the `.*` part with the file's actual name in the browser.

I'm using ubuntu 20.04, nim 1.4.4 and jester 0.5.0.