literalExample is deprecated and overused. See:
https://whetstone.privatestorage.io/privatestorage/PrivateStorageio/-/merge_requests/201#note_16966

Systemd sets soft limits by using a <soft:hard> range, see
https://github.com/systemd/systemd/pull/1994. We want soft
and hard limit to be the same, so we use the IMO defective
former behavior of setting the limit once and have systemd
set both. RedHat Bug 1351415 has more informatin about not
being able to set soft limits within the systemd config in
before https://bugzilla.redhat.com/show_bug.cgi?id=1351415

This removes the code that might delete a Tahoe-LAFS nodedir and replaces it
with code that will try to save an unexpected copy of it out of the way
instead.