lib/config: Revert #5415 (#5417)
lib/config: Revert #5415 (#5417)

This reverts commit 9d075781add838200cb1e50537aa48d3ac1916f4:
"cmd/syncthing: Improve messages when free space is running out (#5415)"
wweich/syncthing,xduugu/syncthing,imsodin/syncthing,syncthing/syncthing,AudriusButkevicius/syncthing,wweich/syncthing,syncthing/syncthing,wweich/syncthing,syncthing/syncthing,xduugu/syncthing,syncthing/syncthing,imsodin/syncthing,wweich/syncthing,imsodin/syncthing,imsodin/syncthing,xduugu/syncthing,imsodin/syncthing,syncthing/syncthing,AudriusButkevicius/syncthing,AudriusButkevicius/syncthing,xduugu/syncthing,syncthing/syncthing,AudriusButkevicius/syncthing