x11/konsole: add usptream patch fix highlight colour contrast

The recent update to x11/konsole included a change which made the
highlight colour very close to the background one in some instances.

The included upstream commit improves the situation again, making
the highlights a higher contrast.

See upstream bug [1] for details.

[1] https://bugs.kde.org/show_bug.cgi?id=435309

Reported by: avg
Obtained from: https://invent.kde.org/utilities/konsole/-/merge_requests/380