Handle zero day expiration logic in code

We got this mail from Transifex:

A resource could not be auto-updated

Transifex was unable to auto update the file Briar Desktop. Fetching from the following URL failed https://code.briarproject.org/briar/briar-desktop/-/raw/main/src/main/resources/strings/BriarDesktop.properties. The error message from the server was:

Invalid plural types for string: expiration.banner.part1. Language supports: ['one', 'other'], but found: ['zero', 'one', 'other'] instead.

Please make sure the URL provided for the file is accessible, or update the link to the file. If you plan to stop auto-update for this file, please disregard this

Fixes #241 (closed)

Closes #241 (closed)