Will not work if multiple MCP inspector windows are open #668

Describe the bug
Not really a bug, it's just been driving me crazy for the past hour and I figured out what the problem was. I had multiple inspector windows open.
To Reproduce

1. uv run mcp dev simple_echo.py
2. Open inspector in a browser
3. Shut down the server using ctrl+c
4. uv run mcp dev simple_echo.py again
5. Observe the errors
   Expected behavior
   It would be nice if it did not do this.
   Screenshots

Desktop (please complete the following information):
Windows 11, Firefox