Open a WebSockets after Uploading a file

**Description**
Attempting to open a WebSocket immediately after uploading a file using an XMLHttpRequest() cause a connection failure.

**To Reproduce**
Steps to reproduce the behavior:
1. Create a WebPage that allow uploading as well as to create a websocket.
2. upload a file using XMLHttpRequest()
3. as soon as upload have been completed then create a WebSocket()
4. See error connection fail.

**Expected behavior**
The connection will be completed sucessfully.

**Additional context**
Webserver have one single listener on port 8080 and different endpoints "/upload_endpoint" used for uploading files, "/output" used for the websockets and "/" that is the default.