ValueError: No JSON object could be decoded

https://sentry.io/lidarr/metadata-api/issues/477218613/

```
ValueError: No JSON object could be decoded
(9 additional frame(s) were not displayed)
...
  File "lidarrmetadata/api.py", line 114, in get_artist_info
    artist['Images'] = artist_art_providers[0].get_artist_images(mbid)

ValueError: No JSON object could be decoded
```