in tabbar - don't show tab background on tab add (plus icon)

Change-Id: Ibe6ff1164382474ff120078bacf28344bc1b1985

svtools/source/control/tabbar.cxx

@@ -1337,7 +1337,6 @@ void TabBar::Paint( const Rectangle& rect )
         // Draw the insert tab at the right end.
         Rectangle aRect = ImplGetInsertTabRect(pItem);
         aDrawer.setRect(aRect);
-        aDrawer.drawTab();
         aDrawer.drawPlusImage();
     }