[BUGFIX] Fix property access for ObjectStorage

When enabling access to the content of ObjectStorages by
integer number, it was overlooked that property access might
be desired too, which has also been working before.

Fix this by not aborting the access when addressing a
non-integer property on ObjectStorages.

Resolves: #59412
Releases: 6.3, 6.2
Change-Id: I59b83ed0bf0c965efcdf0aad9440d634953a221e
Reviewed-on: https://review.typo3.org/31314
Reviewed-by: Anja Leichsenring
Tested-by: Anja Leichsenring