If Unix domain socket file exists then Vapor crashes when starting instead of taking over the socket file

[talmeme]

Describe the bug

In the app's configure.swift, func configure(), set to use Unix domain socket (UDS):

app.http.server.configuration.address = .unixDomainSocket(path: unixDomainSocket)

If the UDS file exists then the app crashes upon start.

To Reproduce

• Create an app to use UDS.
• Start the app.
• Verify that the app created the UDS in the specified path.
• Kill the app so that it doesn't shut down cleanly.
• Verify that the app's UDS still exists.
• Start the app and see that it fails: bind(descriptor:ptr:bytes:): Address already in use (errno: 98) (Vapor/Application.swift:162)

Expected behavior

Vapor removes the old UDS file and recreates it. As per @gwynne on Discord, the bug is at https://github.com/vapor/vapor/blob/main/Sources/Vapor/HTTP/Server/HTTPServer.swift#L421:

channel = bootstrap.bind(unixDomainSocketPath: socketPath)

And the fix:

channel = bootstrap.bind(unixDomainSocketPath: socketPath, cleanupExistingSocketFile: true)

Tested working on my machine.

Environment

OS = Ubuntu 22.04 aarch64
Swift v5.9

    {
      "identity" : "vapor",
      "kind" : "remoteSourceControl",
      "location" : "https://github.com/vapor/vapor.git",
      "state" : {
        "revision" : "036d67e4da46126810f56c6a6ce813bcf259a745",
        "version" : "4.84.1"
      }
    },

[0xTim]

@talmeme if you want to do a PR for this that would be great!