cmake: Don't set the CMakeInstance on the Properties member.

There is no need, as global properties have nowhere to chain up
to.

Source/cmake.cxx

@@ -187,7 +187,6 @@ cmake::~cmake()
 void cmake::InitializeProperties()
 {
   this->Properties.clear();
-  this->Properties.SetCMakeInstance(this);
   this->PropertyDefinitions.clear();
 
   // initialize properties