added missing ctor implementation

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@38134 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/mac/carbon/display.cpp

@@ -77,7 +77,7 @@ private:
 class wxDisplayFactoryMacOSX : public wxDisplayFactory
 {
 public:
-    wxDisplayFactoryMacOSX();
+    wxDisplayFactoryMacOSX() {}
 
     virtual wxDisplayImpl *CreateDisplay(size_t n);
     virtual size_t GetCount();