The following list is just for me to remember what has to be changed in the forum:

-attachments are not visible forever, but for a limited time sometimes
-the field for writing entries could be larger
-jump to forum box can't be clicked away by using the function which should does it

I got notified that an update from http to safer https in the english (.org) version of the forum software is not yet possible without upgrading to premium, which costs 6.95€ per month.

Therefore I'll leave it as http and hope nobody has a problem with that.
Otherwise, we could try to gather the money, it wouldn't be more than 2-4€ per person monthly if we collect it (just 0.25€ if that many people join the forum as I thought in the beginning)