fix

tools/migrate_db.py

@@ -44,7 +44,7 @@ def migrate_songs():
         for diff in ['easy', 'normal', 'hard', 'oni', 'ura']:
             if row[diff]:
                 spl = None
-                if type(row[diff]) == 'string':
+                if type(row[diff]) == 'str':
                     spl = row[diff].split(' ')
                 else:
                     spl = [row[diff]]