Pontoon: Update Ukrainian (uk) localization of Firefox Screenshots
Pontoon: Update Ukrainian (uk) localization of Firefox Screenshots

Localization authors:
- Artem Polivanchuk <a.polivanchuk@outlook.com>

mozilla-services/pageshot,mozilla-services/pageshot,mozilla-services/screenshots,mozilla-services/pageshot,mozilla-services/screenshots,mozilla-services/pageshot,mozilla-services/screenshots,mozilla-services/screenshots