aqbanking: 5.6.10 -> 5.6.12

 * 5.6.11: Fix problem with some servers aborting SSL connections.
 * 5.6.12: Improve handling of offset accounts during turnover
           retrieval.

The full changelogs in German can be found at:

https://www.aquamaniac.de/sites/news/index.php



Built and tested successfully on my machine.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>