answers in wrong language

Sometimes answers are returned in a different language from the one specified. e.g:

```bash
$ curl cht.sh/python/progress+meter # correctly returns python [so/q/3160699]
$ curl cht.sh/python/progress+bar # incorrectly returns java [so/q/19417246]
```

Start by reproducing both curl requests against cht.sh/python/progress+meter and cht.sh/python/progress+bar, then trace how the requested language is selected for returned answers. Done means the progress+bar request returns a Python answer rather than the Java result, while the existing progress+meter behavior remains correct.

Written by the indexing model from the issue text.