Upgrade to Thunderbird 78 ESR
Thunderbird 78 should be released during the week of 2020-07-06; Thunderbird 68 should become EOL on 2020-09-22, which will be our deadline for upgrading to v78. This should also be the time when built-in OpenPGP support gets enabled by default in Thunderbird 78.2 (#17147).
The two Thunderbird patches we created to replace TorBirdy were upstreamed (#17283 (closed)) and should be part of Thunderbird 78, so they can be dropped from the patches we apply on top. Those are:
In the upstream patches, the pref
split into two new prefs, which have to be enabled instead: