set Autocrypt settings via /etc/thunderbird/prefs/thunderbird.js

patch /usr/share/xul-ext/enigmail/modules/preferences/defaultPrefs.js:

• switch Autocrypt is off by default
• mail.server.default.acPreferEncrypt is true, so if Autocrypt gets enables the “prefer-encrypt=mutual” is set by default.

See #16186-note_3

Feature Branch: hefee/bugfix/16186-disable-autocrypt+force-all-tests

Parent Task: #15923 (closed)

Related issues

• Blocks #15507 (closed)

Original created by @Hefee on 16222 (Redmine)