cmScriptGenerator: Remove unused method.

Source/cmScriptGenerator.h

@@ -54,9 +54,6 @@ public:
   void Generate(std::ostream& os, const std::string& config,
                 std::vector<std::string> const& configurationTypes);
 
-  const std::vector<std::string>& GetConfigurations() const
-    { return this->Configurations; }
-
 protected:
   typedef cmScriptGeneratorIndent Indent;
   virtual void GenerateScript(std::ostream& os);