Logcat: fix dsError color with underline="0"
In itemData's, using dsError with underline="0" doesn't work, the text is underlined.
Therefore, dsError is changed by dsWarning.
I don't know the origin of this bug, this is a temporary solution for the Logcat highlighter.
This bug isn't noticeable in the autotests files, there are no changes when run make test.
Test Plan: make test
Reviewers: Framework: Syntax Highlighting, dhaumann, cullmann
Reviewed By: Framework: Syntax Highlighting, cullmann
Subscribers: kwrite-devel, kde-frameworks-devel
Differential Revision: https://phabricator.kde.org/D19461