[tldoc] [tex-live] program translation po updates

[Karl Berry]

    I can't find where the string "keep arbitrarily many" is used, however, and in
    Italian, without a proper context, translation would be a mess.

FWIW, the .po file shows the source line(s) where a string is used.
In this case, texmf/scripts/texlive/tlmgrgui/gui-config.pl:424.

Anyway, as already replied, it's about the backup options.

Thanks for the update.

Best,
Karl