nbxmpp: 0.6.5 -> 0.6.6

Upstream changes:

  * Record all SSL errors instead of only the first
  * Pass arguments to plugin/plugout methods
  * Allow the Roster to be initalized without requesting it from the
    server

Tested by building and running Gajim 1.0.3.

Signed-off-by: aszlig <aszlig@nix.build>
Cc: @abbradar