Bug 30914: (24153 follow-up) Fix cleanup_database.pl --transfers --old-reserves

Bug 30914: (24153 follow-up) Fix cleanup_database.pl --transfers --old-reserves

Silly mistake, 'delete if verbose' must be 'delete if confirm'

Test plan:
Try the cleanup_database.pl script to delete transfers and old issues.
Using --transfers --old-reserves and the --confirm flag the entries must be
removed

Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>