Warn if multiple servers are configured for autostart on same port

It is possible to configure multiple servers on the same Port and activate Automatically start server in the Server Settings... window for them. Having multiple servers defined on the same port is perfectly fine as long as these are used one after another - if you attempt to do otherwise, the second attempt would fail with error Port in use. But if you set multiple ones to Automatically start server and restart Postgres.app it's not deterministic which one would be successfully started and which one would fail to load, so you may get a different Database every time you start Postgres.app.

I suggest warning the user if in case of such a configuration. E.g. by showing a warning triangle symbol next to the Automatically start server setting if another server already has that active while being configured on the same port.