Refs #4663. When resetting the curve, remove changing its style.

Code/Mantid/MantidPlot/src/Mantid/MantidMatrixCurve.cpp

@@ -251,21 +251,15 @@ void MantidMatrixCurve::dataReset(const QString& wsName)
 
   if (!mws) return;
   const MantidQwtMatrixWorkspaceData * new_mantidData(NULL);
-  try {
+  try 
+  {
     new_mantidData = mantidData()->copy(mws);
     setData(*new_mantidData);
-    if (mws->isHistogramData())
-    {
-      setStyle(QwtPlotCurve::Steps);
-      setCurveAttribute(Inverted,true);// this is the Steps style modifier that makes horizontal steps
-    }
-    else
-    {
-      setStyle(QwtPlotCurve::Lines);
-    }
     // Queue this plot to be updated once all MantidQwtMatrixWorkspaceData objects for this workspace have been
     emit dataUpdated();
-  } catch(std::range_error &) {
+  } 
+  catch(std::range_error &) 
+  {
     // Get here if the new workspace has fewer spectra and the plotted one no longer exists
     Mantid::Kernel::Logger::get("MantidMatrixCurve").information() << "Workspace " << wsNameStd
         << " now has fewer spectra - plotted curve(s) deleted\n";