Display only events on homepage (not "activities")
Before #1112 (closed) events that were started were disappearing from the homepage. Now on-going events appear, but it's not good when some events in the database last from 2019 to 2030 --> they appear first in the homepage, no other event can ever make it to the homepage!
Proposed solution: when "activities" are activated, only display events on the homepage, not activities This way we'll only see one the homepage events that have started less than a month ago, and those are relevant.