Security update for MozillaThunderbird and mozilla-nspr

This update for MozillaThunderbird and mozilla-nspr fixes the following issues: - Mozilla Thunderbird 78.4 * new: MailExtensions: browser.tabs.sendMessage API added * new: MailExtensions: messageDisplayScripts API added * changed: Yahoo and AOL mail users using password authentication will be migrated to OAuth2 * changed: MailExtensions: messageDisplay APIs extended to support multiple selected messages * changed: MailExtensions: compose.begin functions now support creating a message with attachments * fixed: Thunderbird could freeze when updating global search index * fixed: Multiple issues with handling of self-signed SSL certificates addressed * fixed: Recipient address fields in compose window could expand to fill all available space * fixed: Inserting emoji characters in message compose window caused unexpected behavior * fixed: Button to restore default folder icon color was not keyboard accessible * fixed: Various keyboard navigation fixes * fixed: Various color-related theme fixes * fixed: MailExtensions: Updating attachments with onBeforeSend.addListener() did not work MFSA 2020-47 (bsc#1177977) * CVE-2020-15969 Use-after-free in usersctp * CVE-2020-15683 Memory safety bugs fixed in Thunderbird 78.4 - Mozilla Thunderbird 78.3.3 * OpenPGP: Improved support for encrypting with subkeys * OpenPGP message status icons were not visible in message header pane * Creating a new calendar event did not require an event title - Mozilla Thunderbird 78.3.2 (bsc#1176899) * OpenPGP: Improved support for encrypting with subkeys * OpenPGP: Encrypted messages with international characters were sometimes displayed incorrectly * Single-click deletion of recipient pills with middle mouse button restored * Searching an address book list did not display results * Dark mode, high contrast, and Windows theming fixes - Mozilla Thunderbird 78.3.1 * fix crash in nsImapProtocol::CreateNewLineFromSocket - Mozilla Thunderbird 78.3.0 MFSA 2020-44 (bsc#1176756) * CVE-2020-15677 Download origin spoofing via redirect * CVE-2020-15676 XSS when pasting attacker-controlled data into a contenteditable element * CVE-2020-15678 When recursing through layers while scrolling, an iterator may have become invalid, resulting in a potential use-after- free scenario * CVE-2020-15673 Memory safety bugs fixed in Thunderbird 78.3 - update mozilla-nspr to version 4.25.1 * The macOS platform code for shared library loading was changed to support macOS 11. * Dependency needed for the MozillaThunderbird udpate