Fix wxOSX build with wxUSE_DRAG_AND_DROP==0

src/osx/cocoa/dnd.mm

@@ -10,12 +10,12 @@
 
 #include "wx/wxprec.h"
 
+#if wxUSE_DRAG_AND_DROP || wxUSE_CLIPBOARD
+
 #ifndef WX_PRECOMP
 #include "wx/object.h"
 #endif
 
-#if wxUSE_DRAG_AND_DROP
-
 #include "wx/dnd.h"
 #include "wx/clipbrd.h"
 #include "wx/filename.h"
@@ -242,6 +242,7 @@ size_t wxOSXPasteboard::GetItemCount() const
     return [[m_pasteboard pasteboardItems] count];
 }
 
+#if wxUSE_DRAG_AND_DROP
 
 wxDropSource* gCurrentSource = NULL;
 
@@ -512,4 +513,4 @@ wxDragResult wxDropSource::DoDragDrop(int flags)
 }
 
 #endif // wxUSE_DRAG_AND_DROP
-
+#endif // wxUSE_DRAG_AND_DROP || wxUSE_CLIPBOARD