django2.2: replace removed is_anonymous() and is_authenticated to their now used counterparts

core/middleware.py

@@ -37,7 +37,7 @@ AnonymousUser = getattr(importlib.import_module(module), klass)
 def get_cached_user(request):
     if not hasattr(request, "_cached_user"):
         user = get_user(request)
-        if user.is_anonymous():
+        if user.is_anonymous:
             user = AnonymousUser(request)
 
         request._cached_user = user