From Leo and Diego: Add missing include protection

git-svn-id: http://root.cern.ch/svn/root/trunk@22727 27541ba8-7e3a-0410-8455-c3a389f83636

physics/inc/TRobustEstimator.h

@@ -13,6 +13,9 @@
 //
 //////////////////////////////////////////////////////////////////////////////
 
+#ifndef ROOT_TRobustEstimator
+#define ROOT_TRobustEstimator
+
 #include "TArrayI.h"
 #include "TMatrixDSym.h"
 #include "TMatrixDSymEigen.h"
@@ -106,3 +109,5 @@ public:
 };
 
 
+#endif
+