Issue Summary

Importing a Theme with a blank Program field assigns the Program to the selected Program in the import's "Available Programs" prompt.

This is reproducible on Data Center: yes

Steps to Reproduce

1. Export a Theme.
2. Remove Programs from export leaving field blank.
3. Make any other normal change to Theme in export.
4. Import Theme, selecting an available Program as part of the import process.

Expected Results

Blank cells should not update imported work items per https://help.jiraalign.com/hc/en-us/articles/115000088674-Import-objects-via-Excel-overview

Actual Results

Program is updated to just the selected Program from the "Available Program" prompt, removing any other existing programs.

Workaround

When exporting/importing Themes, maintain list of programs instead of leaving programs blank.