fix(tabby): fix swagger's local server use local port

[hufeng]

 servers(
        (url = "https://playground.app.tabbyml.com", description = "Playground server"),
        (url = "http://localhost:8080", description = "Local server"),
    ),

The default is to use port 8080, but serve can customize the port through --port, resulting in request errors

[wsxiaoys]

Thanks for the PR, one nit