Bump aqbanking version to 6.1.2
This fixes a bug with a large german bank (comdirect), see
https://www.aquamaniac.de/rdm/issues/136
Original patch by Matthias Gehre
Reviewers: tbaumgart
Reviewed By: tbaumgart
Tags: KMyMoney
Differential Revision: https://phabricator.kde.org/D27930
(cherry picked from commit 0e4ec2e7b74c5b017839a69c6934b2f13357806b)