fix a typo

src/THcHelicityScaler.h

@@ -50,7 +50,7 @@ public:
   virtual Bool_t IsSeedGood() {return fNBits>=30;}
 
   const std::vector<Double_t> &GetPlusScalers() const { return fHScalers[0]; }
-  const std::vector<Double_t> &GetMinusScalers() const { return fHScalers[0]; }
+  const std::vector<Double_t> &GetMinusScalers() const { return fHScalers[1]; }
   const std::vector<Double_t> &GetScalerSums() const { return fScalerSums; }
   const std::vector<Double_t> &GetAsymmetry() const { return fAsymmetry; }
   const std::vector<Double_t> &GetAsymmetryError() const { return fAsymmetryError; }