Log Message:
firefox78: Update to 78.10.1

Changelog:
Version 78.10.1, first offered to ESR channel users on May 4, 2021

Fixed

  * Resolved an issue caused by a recent Widevine plugin update which prevented
    some purchased video content from playing correctly (bug 1705138)

  * Security fix

Security fixes:
#CVE-2021-29951: Mozilla Maintenance Service could have been started or stopped
 by domain users