Bug 24649: Fix missing <li> tag on item editor for cloned subfield

Bug 24649: Fix missing <li> tag on item editor for cloned subfield

Instead of the parentNode (which is a div), we need the parent of the div
(which is a li).
So a simple fix.

Test plan:
To see the difference, test first without patch applied:
Mark item subfield, say URI, as repeatable.
Clone that subfield in item editor.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Aleisha Amohia <aleishaamohia@hotmail.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>