ignore flake8 `Function is too complex (C901)` for `_webio_handler()`

pywebio/platform/tornado.py

@@ -66,7 +66,7 @@ def _is_same_site(origin, handler: WebSocketHandler):
     return origin == host
 
 
-def _webio_handler(applications=None, cdn=True, reconnect_timeout=0, check_origin_func=_is_same_site):
+def _webio_handler(applications=None, cdn=True, reconnect_timeout=0, check_origin_func=_is_same_site):  # noqa: C901
     """
     :param dict applications: dict of `name -> task function`
     :param bool/str cdn: Whether to load front-end static resources from CDN