tdf#111781 Drawing selection highlight twice in listBoxes

The selection highlight is drawn tiwce: a rectangle and the
background of the text. The fix removes the text backround
by setting it to transparent.

Change-Id: I969cb5b27619df07d0a37f1a38c859dbf2565483
Reviewed-on: https://gerrit.libreoffice.org/47064
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Tamás Zolnai <tamas.zolnai@collabora.com>
diff --git a/vcl/source/control/imp_listbox.cxx b/vcl/source/control/imp_listbox.cxx
index c9d4bab..279a178 100644
--- a/vcl/source/control/imp_listbox.cxx
+++ b/vcl/source/control/imp_listbox.cxx
@@ -1699,7 +1699,6 @@ void ImplListBoxWindow::ImplPaint(vcl::RenderContext& rRenderContext, sal_Int32 
    {
        rRenderContext.SetTextColor(!IsEnabled() ? rStyleSettings.GetDisableColor() : rStyleSettings.GetHighlightTextColor());
        rRenderContext.SetFillColor(rStyleSettings.GetHighlightColor());
        rRenderContext.SetTextFillColor(rStyleSettings.GetHighlightColor());
        rRenderContext.DrawRect(aRect);
    }
    else
@@ -1707,8 +1706,8 @@ void ImplListBoxWindow::ImplPaint(vcl::RenderContext& rRenderContext, sal_Int32 
        ApplySettings(rRenderContext);
        if (!IsEnabled())
            rRenderContext.SetTextColor(rStyleSettings.GetDisableColor());
        rRenderContext.SetTextFillColor();
    }
    rRenderContext.SetTextFillColor();

    if (IsUserDrawEnabled())
    {