fix qt seed dialog (follow-up af86c7e3fd)

electrum/gui/qt/seed_dialog.py

@@ -152,7 +152,7 @@ class SeedLayout(QVBoxLayout):
         bip39_english_list = Mnemonic('en').wordlist
         old_list = electrum.old_mnemonic.words
         only_old_list = set(old_list) - set(bip39_english_list)
-        self.wordlist = bip39_english_list + list(only_old_list)  # concat both lists
+        self.wordlist = list(bip39_english_list) + list(only_old_list)  # concat both lists
         self.wordlist.sort()
 
         class CompleterDelegate(QStyledItemDelegate):

electrum/mnemonic.py

@@ -93,7 +93,7 @@ def normalize_text(seed: str) -> str:
 _WORDLIST_CACHE = {}
 
 
-def load_wordlist(filename):
+def load_wordlist(filename) -> tuple:
     path = resource_path('wordlist', filename)
     if path not in _WORDLIST_CACHE:
         with open(path, 'r', encoding='utf-8') as f: