Don't use wxSharedPtr<> in factory registration code

Shared ownership semantics again seems inappropriate here as we're not
actually sharing the pointers here, so just use raw pointers instead
(with C++11 we could use std::unique_ptr<>, but this is impossible with
our own map and scoped pointer implementations).

No real changes.

include/wx/webrequest.h

@@ -16,7 +16,6 @@
 
 #include "wx/event.h"
 #include "wx/object.h"
-#include "wx/sharedptr.h"
 #include "wx/stream.h"
 #include "wx/versioninfo.h"
 
@@ -216,7 +215,7 @@ public:
 
 private:
     static void RegisterFactory(const wxString& backend,
-                                const wxSharedPtr<wxWebSessionFactory>& factory);
+                                wxWebSessionFactory* factory);
 
     static void InitFactoryMap();