Use the default Web sockets implementation for HMR

[lslezak]

Changes

• Use the default web sockets implementation for the hot reload / hot module replacement when running the Webpack development server
• Removed server: "http" option, that's the default, this setting is not need anymore (it was needed for using https with Cockpit)

Details

Cockpit requires web socket with SSL when talking to the server and that required to run the Webpack server with SSL as well. But in that case hot reload did not work because it also uses a web socket but it does not support SSL.

As a workaround the hot reload was switched to the sockjs implementation which emulates web sockets using plain http/https connection. Using web sockets for hot reload is more used and tested (it's the default) so I guess it could be more reliable than that sockjs emulation. So this might (or might not...) fix some problems with hot reload getting stuck in some cases.

[lslezak]

Ah, unfortunately it does not fix the problem, it still freezes when modifying web/src/client/storage.js 😟

But at least it uses more standard implementation so I still think it makes sense to update it.