Thanks for the ideas everyone.
I did use rebuild app. And if Discourse installs nothing extra (was thinking nginx and Apache2 would come by default because of something new)… hmmm. I certainly haven’t added Apache2 myself.
Ah. After having this DigitalOcean Ubuntu for Discourse only for years and years I actually installed Subversion in January, apparently without rebooting. That install apparently adds Apache although disabling it still leaves me with the functionality I need.
Guess I’m not so used to installs adding garbage (yes I’m sure Apache is needed for something). That more commonly happens on like, Windows or Android 
.
Sorry for the trouble. Then again, this is a real use case scenario, always good to read those as a developer.