[BUG] Original_year set to 0 in deezer plugin and as-is

[arogl]

I have noticed that the original_year is set to 0 when using the deezer plugin as well as an 'as-is' import.

In my config I do not have original_date set, so assume it has defaulted to no.

In the discogs plugin I notice orginal_year is explicitly set to year when no master recording is set.

Do we need to add similar lines to the other plugins?

Related to this is if I set the orginal_year in MP3 tag to match year, on a beet update the year, month and date tags get set to 0.

[sampsyo]

0 is the default value, so that is what will happen if a backend doesn't provide an original year. Collecting that information from other backends would always be a useful feature!

The original_date config option causes year to contain the earlier release date, i.e., what would otherwise just go in original_year.