Log Message:
thunderbird: Upgrade to 68.1.2

Local changes
=============

Cherry-pick a pending patch to fix build with the recent rust version (1.38.0).

esr68 branch fails to build with rust 1.38
https://bugzilla.mozilla.org/show_bug.cgi?id=1585099

Cherry-pick patch from:
https://marc.info/?l=openbsd-ports&m=156984549605237&w=2

Upstream changelog
==================

What's New

    fixed Visual glitches: Missing context menu in filter, downloads, password \ 
manager and Config Editor search boxes, unwanted scrollbars and cut-off text in \ 
Account Manager, incorrect colors in Calendar agenda scrollbars, theme issues on \ 
Windows 7
    fixed Some attachments couldn't be opened in messages originating from MS \ 
Outlook 2016
    fixed Address book import form CSV
    fixed Performance problem in message body search
    fixed Ctrl+Enter to send a message would open an attachment if the \ 
attachment pane had focus
    fixed Calendar: Issues with "Today Pane" start-up
    fixed Calendar: Glitches with custom repeat and reminder number input
    fixed Calendar: Problems with WCAP provider

https://www.thunderbird.net/en-US/thunderbird/68.1.2/releasenotes/