[gnote] Remove has_window from NoteAddin

[Aurimas Černius <aurimasc src gnome org>]

commit c277c680992679fda9614f9bc4c05e78dd23d662
Author: Aurimas Černius <aurisc4 gmail com>
Date:   Sat Jul 17 21:51:03 2021 +0300

    Remove has_window from NoteAddin

 src/noteaddin.hpp | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)
---
diff --git a/src/noteaddin.hpp b/src/noteaddin.hpp
index 44376f39..50e854cd 100644
--- a/src/noteaddin.hpp
+++ b/src/noteaddin.hpp
@@ -1,7 +1,7 @@
 /*
  * gnote
  *
- * Copyright (C) 2012-2016,2019 Aurimas Cernius
+ * Copyright (C) 2012-2016,2019,2021 Aurimas Cernius
  * Copyright (C) 2009 Hubert Figuiere
  *
  * This program is free software: you can redistribute it and/or modify
@@ -89,10 +89,6 @@ public:
       }
       return m_note->get_buffer();
     }
-  bool has_window() const
-    {
-      return m_note->has_window();
-    }
   NoteWindow * get_window() const
     {
       if(is_disposing() && !has_buffer()) {