rsbackup(1) --retire option still suggests manually removing db records rather than --forget-only

[pm215]

When the --forget-only option was added, the rsbackup(1) manpage was updated with documentation for that option, but the --retire option still suggests manual DB manipulation. I suggest that this bit:

If you just want to remove backup records for retired volumes but want to keep the backups, you should either manually remove the records (see SCHEMA below), or rename it within the volume.

be changed to something like:

If you just want to remove backup records for retired volumes but want to keep the backups, you should either pass the --forget-only option as well, or rename it within the volume.

Or maybe drop the bit about renaming -- I'm not sure what the referent of "it" is in that part of the sentence so it could maybe use clarification if you want to keep it.

Section 3.4 "Retired volumes" of rsbackup-manual could also helpfully mention --forget-only.