Recover from SSL error during tweet's mf2 discovery

In the end, the problem was an SSL error (ccc got a funky cert), and there was no except clause for it.
This fixes the *crash* reported in #28, but those `During handling of the above exception, another exception occurred` messages are still there (apparently, the crash wasn't because of that). I have a theory what the problem could be, so I'll comment at #28.