Fix client socket defaults for websocket transport

[chmielowiec]

After latest refactor websocket transport is broken again

[frederikaalund]

Hi Robert, thanks for the pull request. Let me have a look. :)

Nice catch! 👍 That if statement is a mistake on my part. I simply forgot to put a not in front. Can we change it to the following:

if not isinstance(client_socket, socket.socket):

Note the not in front of isinstance.

[chmielowiec]

Changed according to your review.