Fix code comment for frontend ports

[NobodysNightmare]

This was most likely a copy & paste mistake.

Looking at this, I am still wondering whether more guidance would be useful on when to use which port to access the application. The comments in the docker-compose.override.example.yml merely state the obvious ("these things are port mappings"). But if I am asking myself whether I should access the app via port 3000 or 4200, I am lost.

Elsewhere I can find:

You can now access OpenProject under http://localhost:3000/, and via the live-reloaded under http://localhost:4200/.

So there seems to be no big difference between the two? However, @mereghost wrote me in a DM:

Accessing by 3000 will break most of the pages that have angular components

So my take is, that for anything where I access the UI, 4200 is preferable?

Merge checklist

• Added/updated tests
• Added/updated documentation in Lookbook (patterns, previews, etc)
• Tested major browsers (Chrome, Firefox, Edge, ...)

[Kharonus]

TBH, I took the step back and no longer use localhost at all to access the app. I have the reverse proxy in place, which we set up for TLS, and I use the DNS specified there to access my app.

This allows me also, to up and run different stacks, without changing port bindings around.

[NobodysNightmare]

@Kharonus Yeah, that's a fair point. I also realized (once digging into the TLS setup) that the frontend container is the one receiving the labels for Traefik, which then answers the question "which one to use" as well.

I'll leave it at that for now and not dig deeper into further doc improvements (as suggested by my PR description).