Fixing questioncache to not reutrn nil on clear
Fixing questioncache to not reutrn nil on clear

When using grimer and reaper together, a fun race condition can be triggered when clearing the question cache.

Immediately after the questioncache is cleared, the response gives the following:

```json
{
				items: null,
				length: 0,
}
```

Which would be fine, but reaper uses length on the JSON.parsed `items` of that result.

Since the likely hood of a new DNS question is low between the time clear is clicked and a refresh occurs, reaper often panics trying to get `length` of `null`.

Steps to reproduce:

1. Start server
2. curl localhost:8080/questioncache (note items is `[]`
3. curl localhost:8080/questioncache/clear
4. curl localhost:8080/questioncache (note items is `null`

Hopefully this patch finds you well, and happy #hacktoberfest!

looterz/grimd