Handle Missing year for unconfirmed / unknown releases

[gotson]

As highlighted in #15 unconfirmed or unknown releases cannot be uploaded because of the missing year, which is mandatory, but those are still being transcoded, wasting some CPU time for nothing.

This PR introduces a new command line argument -Y or --force-year:

• when set, the transcode will happen like before, but the upload will be done by forcing the year of the torrent by using the one of the group. The problem with that is the new torrent will not be in the same group has the source of the transcode. This should require a manual action from staff to correct the newly added torrent and mark it as Unconfirmed.
• when not set (default), the whole torrent will be skipped entirely, and won't be transcoded.

Closes #15

For those interested, those changes are included in my Docker image: gotson/redbetter:latest