7097: EditNote hangs initially on misspelled note

Disable undo during the initial note text population,
so as to avoid bombardment with gtkspell-... tags for the
misspelled text.

gramps/gui/editors/editnote.py

@@ -269,6 +269,7 @@ class EditNote(EditPrimary):
         # setup initial values for textview and textbuffer
         if self.obj:
             self.empty = False
+            with self.texteditor.undo_disabled():
                 self.texteditor.set_text(self.obj.get_styledtext())
             # Reset the undoable buffer:
             self.texteditor.reset()