Remove duplicate IMPLEMENT_DYNAMIC_CLASS() for wxGtkCalendarCtrl.

wxIMPLEMENT_DYNAMIC_CLASS_XTI(wxCalendarCtrl) in the common code makes the use
of IMPLEMENT_DYNAMIC_CLASS() in wxGTK implementation unnecessary.

This fixes wxGTK linking.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@66568 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/calctrl.cpp

@@ -171,7 +171,4 @@ void wxGtkCalendarCtrl::Mark(size_t day, bool mark)
         gtk_calendar_unmark_day(GTK_CALENDAR(m_widget), day);
 }
 
-IMPLEMENT_DYNAMIC_CLASS(wxGtkCalendarCtrl, wxControl)
-
-
 #endif // wxUSE_CALENDARCTRL