gajim: 0.16.8 -> 0.16.9

Upstream changes:

  * Improve Zeroconf behavior
  * Fix showing normal message event
  * remove usage of OpenSSL.rand
  * a few minor bugfixes

The really important part here is the third point about OpenSSL.rand,
because the rand attribute no longer exists in pyopenssl and thus Gajim
doesn't even start.

Also the fix-tests.patch has been fixed upstream as well, so we don't
need it anymore.

Another change in 0.16.9 that's not included in the changelog is that
there is a test_nogui target, which is also run by the CI upstream is
using, so let's use that and remove xvfb_run.

Signed-off-by: aszlig <aszlig@nix.build>
Cc: @7c6f434c, @Mic92