Security update for MozillaThunderbird

This update for MozillaThunderbird fixes the following issues: - Firefox was updated to 78.10.0 ESR (bsc#1184960) * CVE-2021-23994: Out of bound write due to lazy initialization * CVE-2021-23995: Use-after-free in Responsive Design Mode * CVE-2021-23998: Secure Lock icon could have been spoofed * CVE-2021-23961: More internal network hosts could have been probed by a malicious webpage * CVE-2021-23999: Blob URLs may have been granted additional privileges * CVE-2021-24002: Arbitrary FTP command execution on FTP servers using an encoded URL * CVE-2021-29945: Incorrect size computation in WebAssembly JIT could lead to null-reads * CVE-2021-29946: Port blocking could be bypassed * CVE-2021-29948: Race condition when reading from disk while verifying signatures This update was imported from the SUSE:SLE-15-SP2:Update update project.