`listTorrents` doesn't respect empty strings as valid inputs for `category` and `tag`

[fr3fou]

https://github.com/qbittorrent/qBittorrent/wiki/WebUI-API-(qBittorrent-4.1)#get-torrent-list

Both the tag and category fields can accept an empty string, which the current implementation completely ignores:

https://github.com/scttcper/qbittorrent/blob/593035a94b470a1e01cb4eab3c6850ec841613a5/src/qbittorrent.ts#L172-L178

[scttcper]

:tada: This issue has been resolved in version 5.2.0 :tada:

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot :package::rocket:

[scttcper]

Thanks for reporting, just as a heads up, this client does not seem to work well with the recently released version of qbittorrent 4.5