Downstream initialize items are not correctly resolved when property hippo:status is missing

Upgrades to 7.9 from projects that started before 7.8 are broken in repository versions 2.26.06 - 2.26.08 because downstream items are not resolved when an initialize item is missing the hippo:status property.

To resolve downstream items a query is done with the clause "hippo:status <> 'missing'". Apparently this clause doesn't match on nodes where the hippo:status property is missing and we must explicitly include this case: "hippo:status <> 'missing' OR hippo:status IS NULL"