Security update for MozillaThunderbird

This update for MozillaThunderbird fixes the following issues: Thunderbird 63 ESR was updated to version 60.3.0 to fix the following issues (bsc#1112852): Security issues fixed (MFSA 2018-28): - CVE-2018-12389: Fixed memory safety bugs. - CVE-2018-12390: Fixed memory safety bugs. - CVE-2018-12391: Fixed HTTP Live Stream audio data is accessible cross-origin. - CVE-2018-12392: Fixed crash with nested event loops. - CVE-2018-12393: Fixed integer overflow during Unicode conversion while loading JavaScript. Non-security issues fixed: - various theme fixes - Shift+PageUp/PageDown in Write window - Gloda attachment filtering - Mailing list address auto-complete enter/return handling - Thunderbird hung if HTML signature references non-existent image - Filters not working for headers that appear more than once - Update _constraints for armv6/7 - Add memory-constraints to avoid OOM errors