Give a warning about Whisperfish being a third-party application

I would want these items to be written carefully:

• Whisperfish is a third-party application, no support from Signal LLC.
• If you need Signal for life-threatening situations, do not use Whisperfish.
• In order not to lose messages, consider having Signal Desktop ready.

This message should reappear any time the text or current translation has changed on the start of the application.