URLM_UNDO_DELETE [-yes]

Undo the last /urlm_list -delete operation. There is only one level of
undo, and you can't undo the undo.

If any URLs have been captured since the last -delete, /urlm_undo_delete
will warn of this fact and refuse to restore, unless -yes is given. If
you override the warning with -yes, you WILL lose any URLs that have been
captured since the delete.