Merge branch 'indices-virtual-dtor' into 'develop'

Add virtual descructor to RadiometricIndex abstract base class

See merge request orfeotoolbox/otb!494

Modules/Radiometry/Indices/include/otbRadiometricIndex.h

@@ -70,6 +70,9 @@ public:
 
   static constexpr double Epsilon = 0.0000001;
 
+  // Necessary to be used as an abstract base class
+  virtual ~RadiometricIndex() = default;
+
   /**
    * \param requiredBands the set<CommonBandNames> of required bands
    * \throw runtime_error if requiredBands contains CommonBandNames::MAX