[git 6120c8644] Assertion hit when using ssl

Hi Heinrich.  Just pulled again today for testing purposes and I'm hitting
an assertion I've never seen before:

** (pan:6114): WARNING **: The certificate is not trusted.


** (pan:6114): WARNING **: The certificate hasn't got a known issuer.

pan: ../../../pan/data-impl/server.cc:209: virtual void pan::DataImpl::save_server_info(const pan::Quark&): Assertion `s' failed.
Aborted

This happens immediately after clicking on the "accept" button in
the certificate dialog box.  Technically the cert dialog box should
not pop up because the flags for that news server are already set:
    <use-ssl>1</use-ssl>
    <trust>1</trust>

I notice that pan correctly re-saves the same settings before hitting
the assertion.  (At least the time stamp on servers.xml is updated to
the current time.)

This particular cert is actually expired and I suspect the cert dialog
box is opening for that reason even though the 'trust' flag is already
set to 1.  I've seen this since I started using your gnutls code but
the assertion appeared today for the first time.  No idea why.

(BTW, news.gmane.org works correctly with ssl because their cert isn't
expired :)