Fixed scrollbar background bug for transparent Konsole
Summary:
In D11184 a visual glitch was introduced when using transparent
background in Konsole.
BUG: 391788
FIXED-IN: 18.04
Test Plan:
Before:
Opaque, there was no problem here
Transparent, obvious problem
After:
Opaque, nothing changes here
Transparent, problem fixed
Reviewers: hindenburg, Konsole
Reviewed By: hindenburg, Konsole
Subscribers: Konsole
Tags: Konsole
Differential Revision: https://phabricator.kde.org/D11839
(cherry picked from commit 88b9cf197f8d2edb3e83c155d25fa562b3fda061)