cmake: Remove unused member.

Source/cmake.cxx

@@ -188,7 +188,6 @@ void cmake::InitializeProperties()
 {
   this->Properties.clear();
   this->Properties.SetCMakeInstance(this);
-  this->AccessedProperties.clear();
   this->PropertyDefinitions.clear();
 
   // initialize properties

Source/cmake.h

@@ -383,7 +383,6 @@ protected:
   void InitializeProperties();
   int HandleDeleteCacheVariables(const std::string& var);
   cmPropertyMap Properties;
-  std::set<std::pair<std::string,cmProperty::ScopeType> > AccessedProperties;
 
   std::map<cmProperty::ScopeType, cmPropertyDefinitionMap>
   PropertyDefinitions;