Re #12917 Made IMDWorkspace copy constructor protected.

Code/Mantid/Framework/API/inc/MantidAPI/IMDWorkspace.h

@@ -70,7 +70,6 @@ enum MDNormalization {
 class MANTID_API_DLL IMDWorkspace : public Workspace, public API::MDGeometry {
 public:
   IMDWorkspace();
-  IMDWorkspace(const IMDWorkspace &other);
   virtual ~IMDWorkspace();
 
   /// Get the number of points associated with the workspace.
@@ -134,6 +133,7 @@ public:
   virtual MDNormalization displayNormalization() const;
 
 protected:
+  IMDWorkspace(const IMDWorkspace &other);
   virtual const std::string toString() const;
 };