Logcat: fix dsError color with underline="0"

Summary:
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

Tags: Kate, Frameworks

Differential Revision: https://phabricator.kde.org/D19461