This update for MozillaThunderbird fixes the following issues:

- Mozilla Thunderbird 78.8
* fixed: Importing an address book from a CSV file always reported an error
* fixed: Security information for S/MIME messages was not displayed correctly prior to a draft being saved
* fixed: Calendar: FileLink UI fixes for Caldav calendars
* fixed: Recurring tasks were always marked incomplete; unable to use filters
* fixed: Various UI widgets not working
* fixed: Dark theme improvements
* fixed: Extension manager was missing link to addon support web page
* fixed: Various security fixes
MFSA 2021-09 (bsc#1182614)
* CVE-2021-23969: Content Security Policy violation report could have contained the destination of a redirect
* CVE-2021-23968: Content Security Policy violation report could have contained the destination of a redirect
* CVE-2021-23973: MediaError message property could have leaked information about cross-origin resources
* CVE-2021-23978: Memory safety bugs fixed in Thunderbird 78.8

This update was imported from the SUSE:SLE-15-SP2:Update update project.