error adding torrent: File exists (os error 17)

[milahu]

adding a torrent with POST /torrents fails with http status 400 and the response text

{"error_kind":"internal_error","human_readable":"error adding torrent: File exists (os error 17)","status":400,"status_text":"400 Bad Request"}

... when these cache files already exist

~/.cache/rqbit/{btih}.bitv
~/.cache/rqbit/{btih}.torrent

workaround: remove the cache files and retry adding the torrent