As rbfeeder was just updated and i don't like my journal / log being spammed that much, here is a solution that will persevere any updates:
sudo mkdir /etc/systemd/system/rbfeeder.service.d
sudo nano /etc/systemd/system/rbfeeder.service.d/no-log.conf
Paste the following:
[Service]
StandardOutput=null
Ctrl-x to exit, y (yes) and enter to save!
Just do a reboot for it to take effect:
sudo reboot