kmymoney: Fix build with Qt 5.11

It's a really small fix that even could have been done via sed, but I'm
using the upstream patch instead so that once a new upstream release
comes along we don't forget to drop the patch.

The patch is from the upstream commit at:

https://cgit.kde.org/kmymoney.git/commit/?id=e5198a902996b27bf9abde0ad24af82d55ab5dc1



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