Overview: When you want to create an item connected to an existing holdings, you match to that holdings hrid and have an action to create item. If you try to create it Item will be errored with NullException in JSON log

Steps to Reproduce:

1. In Inventory, find or create an instance that has a holdings, but no item record

2. Go to Settings/Data Export

3. Create a new mapping

   1. SRS and Holdings

   2. Map Holdings HRID to 901$a

   3. Map Holdings Id to 902$a

4. Create a new data export job linked to that mapping

5. Go to Settings/Data Import

6. Create a new field mapping for an item

   1. Item mat type: Electronic resource

   2. Loan type: Can circulate

   3. Status: Available

7. Create a new action "Create item" linked to that item field mapping

8. Create a new match for 901$a to Holdings hrid

9. Create a new job with that match and on matches, Creates item record

10. Go to Inventory

11. Find or create a Source = MARC Instance with 1 holdings record and no item records

12. Copy that Instance HRID and search for it in Inventory, so that you have only 1 search result

13. Go to Actions/Save instance UUIDs

14. Go to Data Export

15. Upload the UUIDs text file that was just downloaded

16. Apply the export job profile created in step 4 and export the file

17. Download the newly-created MARC file

18. Go to Data Import

19. Upload that exported mrc file and select test job to create item

Expected Results: Item is created. No SRS and Instance records created 

Actual Results:

Item is not created. {*}{{*}}NullException error appears in JSON log.