Before this change, the application

```swift
let app = Application(.testing)
defer { app.shutdown() }
try app.server.start(hostname: nil, port: 0)
defer { app.server.shutdown() }
```

would log the following message *before* starting the server:

```
[Vapor] Server starting on http://127.0.0.1:0
```

After this change it instead logs a message like the following *after* starting the server:

```
[Vapor] Server started on [IPv4]127.0.0.1/127.0.0.1:57935
```

Just invoking the property twice seemed cleaner to me compared to duplicating the code block. Fixed a little indentation issue in the process

I don't know if it's ever relevant, but config is now patched on all address types, including unix socket.