The demise of echo.websocket.org broke the winhttp tests

[Hans Leidekker]

On Tue, 2021-09-21 at 17:04 +0200, Francois Gouget wrote:
> I mentioned this a few times before on IRC and in a bug report but 
> apparently I had not yet reported it to the mailing list.
> 
> echo.websocket.org has been offline for over a month and I have seen no 
> sign that it would ever come back. The end result is that 
> winhttp:winhttp and winhttp:notification now fail systematically.
> 
> So I really need someone to figure out how to replace it.

Looks like ws.ifelse.io could replace it, however it triggers a bug in
our websocket implementation that needs to be fixed first. I'm working
on it.