loplugin:unusedfields in SvxPixelCtl

aLineColor is unused since

    commit fa1807ad
    Date:   Thu Aug 27 21:18:58 2015 +0300
    tdf#93558 Hardcode black text on white background

Change-Id: Idadfa926808568195256c7ea7ac92d71533fe9a9

include/svx/dlgctrl.hxx

@@ -153,7 +153,6 @@ protected:
     sal_uInt16      nLines, nSquares;
     Color       aPixelColor;
     Color       aBackgroundColor;
-    Color       aLineColor;
     Size        aRectSize;
     sal_uInt16* pPixel;
     bool        bPaintable;

svx/source/dialog/dlgctrl.cxx

@@ -806,7 +806,7 @@ void SvxPixelCtl::Paint( vcl::RenderContext& rRenderContext, const tools::Rectan
     if (bPaintable)
     {
         // Draw lines
-        rRenderContext.SetLineColor(aLineColor);
+        rRenderContext.SetLineColor(Color());
         for (i = 1; i < nLines; i++)
         {
             // horizontal