Bug 1799735 - Port bug 1356331: Remove hotfix preferences. r=aleca

The hotfix code was removed from toolkit in milestone 60. There's no reason to
keep these prefs around.

Differential Revision: https://phabricator.services.mozilla.com/D161619

--HG--
extra : amend_source : 556aa42e2ed3dc0cec4c353ec41fceec90028b0d

mail/app/profile/all-thunderbird.js

@@ -148,11 +148,6 @@ pref("extensions.update.autoUpdateDefault", true);
 
 pref("extensions.systemAddon.update.enabled", true);  // See bug 1462160.
 
-pref("extensions.hotfix.id", "thunderbird-hotfix@mozilla.org");
-pref("extensions.hotfix.cert.checkAttributes", true);
-pref("extensions.hotfix.certs.1.sha1Fingerprint", "91:53:98:0C:C1:86:DF:47:8F:35:22:9E:11:C9:A7:31:04:49:A1:AA");
-pref("extensions.hotfix.certs.2.sha1Fingerprint", "39:E7:2B:7A:5B:CF:37:78:F9:5D:4A:E0:53:2D:2F:3D:68:53:C5:60");
-
 // Disable add-ons installed into the shared user and shared system areas by
 // default. This does not include the application directory. See the SCOPE
 // constants in AddonManager.jsm for values to use here