An object returned by XCollection::Item() is of the right "VBA" kind
that we want. One returned by XEnumeration::nextElement() is not.

Change-Id: I26132a7d0f2638a61f2711b941386a889fabea72
Reviewed-on: https://gerrit.libreoffice.org/55392Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Tor Lillqvist <tml@collabora.com>