[Windows] Doesn't bind on IPv4 localhost

[junhaoliao]

Platform: Windows
Python Version: v3.9.5

It seems that on Windows the server doesn't bind on IPv4 localhost(127.0.0.1) by default, when the server address is ''.

Here is a screenshot showing a TCP connection reset when I was using a Postman's WebSocket request to connect to the server with address "ws://localhost:8000".

The binding of "ws://[::1]:8000" is valid though".