Fix the secure Thunderbird autoconfig wizard patchset

Something is wrong with the secure autoconfig wizard in 60.5.1-1~deb9u1.0tails1: #16422-note_24. Initial testing results suggest that there is a bug in Thunderbird itself and another one in our patchset.

It might be that a newer Thunderbird (60.6 or 66) would fix it.

Related issues

Related to #16422 (closed)
Blocks #15507 (closed)

Original created by @intrigeri on 16570 (Redmine)

Edited Nov 22, 2019 by intrigeri

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