Comment 4 for bug 810290

With the feature rule in place process-mail.py OOPSed:
https://pastebin.canonical.com/50633/ (sorry, internal only, and via
pastebin because it doesn't seem to be available at the usual
place). Here's the traceback though:

    Traceback (most recent call last):
      Module lp.services.mail.incoming, line 380, in handleMail
        signature_timestamp_checker)
      Module lp.services.mail.incoming, line 458, in handle_one_mail
        mail, signature_timestamp_checker)
      Module lp.services.mail.incoming, line 218, in authenticateEmail
        dkim_result = _authenticateDkim(mail)
      Module lp.services.mail.incoming, line 130, in _authenticateDkim
        if getFeatureFlag('mail.dkim_authentication.disabled'):
      Module lp.services.features, line 237, in getFeatureFlag
        return features.getFlag(flag)
      Module lp.services.features.flags, line 229, in getFlag
        return self._known_flags.lookup(flag)
      Module lp.services.features.flags, line 149, in lookup
        v = self._calc(key)
      Module lp.services.features.flags, line 235, in _checkFlag
        if self._known_scopes.lookup(scope):
      Module lp.services.features.flags, line 149, in lookup
        v = self._calc(key)
    TypeError: 'ScopesForMail' object is not callable

I've attached the original message.