856/Folio: do not duplicate 856 entries for the same druid

[andrewjbtw]

When an item that has been released is released again, do not create additional 856 records referring to the same druid.

For example, I released https://argo-qa.stanford.edu/view/druid:qq019rq5469 multiple times:

• initial release
• second release with no change (resulting in identical 856)
• third release after changing the rights (different 856)

Each release should have left only one 856 on the MARC record. But the MARC (folio-test link) looks like this:

856 | 4 1 | ‡u https://sul-purl-stage.stanford.edu/qq019rq5469 ‡x SDR-PURL ‡x item ‡x rights:world
856 | 4 1 | ‡u https://sul-purl-stage.stanford.edu/qq019rq5469 ‡x SDR-PURL ‡x item ‡x rights:world
856 | 4 1 | ‡u https://sul-purl-stage.stanford.edu/qq019rq5469 ‡x SDR-PURL ‡x item

[mjgiarlo]

@andrewjbtw I can no longer reproduce this with the test object in QA. Can you?

[andrewjbtw]

This is now working in QA.

[mjgiarlo]

Thank you! Closing.