Roll back libwebsockets to version 3.0.1

[Faless]

This reverts commit 90210c4.

Fixes #27560 while we transition to wslay (a potential cherry pick for godot 3.1.2).

I would like interested parties to test this a bit before we decide what to do (@AshfordN , @RyanJEC, ...).

[akien-mga]

Fine with me as currently we can't build distro packages against system libwebsockets anyway due to the messy openssl-to-mbedtls wrapper.

[AshfordN]

I've tested this and, as far as I can see, it seems to be working perfectly.

[ghost]

Tested, confirmed wss://echo.websocket.org is no longer disconnecting along with my custom websocket server.

However still getting immediate disconnect using wss://irc-ws.chat.twitch.tv Hopefully this will be fixed further after wslay transition.

All in all good patch/revert.

[AshfordN]

@RyanJEC are you certain your twitch disconnect is actually caused by the connection: close header? Websocket connections are also dropped due to incorrect protocol(s) as well. I'm assuming a service like twitch might define its own protocol, so it might be useful to double check.

[ghost]

@AshfordN Honestly I don't know what is going on with twitch ws server. All I know is it connects no problem with browser implementation. I'll probably just use TCP or godot twitch plugin.

I would investigate it but I don't know where or how to start.

This patch works with most servers now. That's all that matters.

[akien-mga]

Thanks!

[akien-mga]

Cherry-picked for 3.1.2.