Pontoon: Update Bulgarian (bg) localization of Firefox Screenshots
Pontoon: Update Bulgarian (bg) localization of Firefox Screenshots

Localization authors:
- Ognyan Kulev <ognyan@ognyankulev.com>
- Aleksandar Ivanov <aleeekc@abv.bg>

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