Remove default parameters from K_CorrelationModel

Resolves #1131 (closed)

Sample/Interface/AutocorrelationModels.h

@@ -44,7 +44,7 @@ protected:
 //! 14472-14478 (1993)
 class K_CorrelationModel : public AutocorrelationModel {
 public:
-    K_CorrelationModel(double sigma = 0, double hurst = 0.7, double lateralCorrLength = 25,
+    K_CorrelationModel(double sigma, double hurst, double lateralCorrLength,
                        double maxSpatFrequency = 0.5);
     std::string className() const override { return "K_CorrelationModel"; }
     std::vector<ParaMeta> parDefs() const final;