title: Cypress web sockets error: 'Sec-WebSocket-Accept' header is missing
body: <p>I am trying to test a VueJs application with Cypress.</p>
  <p>Everything works well except the websocket connection that fails with the message:</p>
  <p><code>Error during WebSocket handshake: 'Sec-WebSocket-Accept' header is missing</code></p>
  <p>On dev or deployed, it works without issue and the 'Sec-WebSocket-Accept' header is present but no clue why it fails with Cypress.</p>
  <p>Any idea?</p>