Test fails with Thunderbird 91.3.4 (64-bit)

[superbonaci]

Console log (Ctrl+Shift+J):

ExtensionError: No such native application open_with ExtensionUtils.jsm:58:5
    ExtensionError resource://gre/modules/ExtensionUtils.jsm:58
    startupPromise resource://gre/modules/NativeMessaging.jsm:83
this.ports.get(...) is undefined ExtensionParent.jsm:366
    recvPortMessage resource://gre/modules/ExtensionParent.jsm:366
    recvPortMessage self-hosted:1175
    _recv resource://gre/modules/ConduitsChild.jsm:78
    receiveMessage resource://gre/modules/ConduitsParent.jsm:385