libwebsockets: 2.3.0 -> 2.4.1

Semi-automatic update. These checks were performed:

- built on NixOS
- found 2.4.1 with grep in /nix/store/lm20nl7bdr3fmnagp48b4a7pjagv5qdf-libwebsockets-2.4.1
- found 2.4.1 in filename of file in /nix/store/lm20nl7bdr3fmnagp48b4a7pjagv5qdf-libwebsockets-2.4.1

cc ""