make sure we normalize deck names on input

https://anki.tenderapp.com/discussions/ankidesktop/31635-anki-crashes-when-new-card-is-added

anki/decks.py

@@ -131,6 +131,7 @@ def flush(self):
     def id(self, name, create=True, type=defaultDeck):
         "Add a deck with NAME. Reuse deck if already exists. Return id as int."
         name = name.replace('"', '')
+        name = unicodedata.normalize("NFC", name)
         for id, g in list(self.decks.items()):
             if unicodedata.normalize("NFC", g['name'].lower()) == name.lower():
                 return int(id)