Subtask shows unsupported messages for sprint field in post migration report when migrating to cloud

Issue Summary

Subtask show unsupported messages for sprint field in post migration report after migrating to cloud. It makes customer confusing.

Unsupported ABC5OPE Issue ABC5OPE-38 Custom field value The "Sprint" custom field is not supported via migration

Steps to Reproduce

• Migrate tickets linking with a Sprint, and the ticket has some subtask.

Expected Results

No error report since sprint it supported by cloud migration, and sprint field is actually set for those ticket after migration.

Actual Results

Below message is written into Requires attention_Post-migration report for each subtask.

Unsupported	ABC5OPE	Issue	ABC5OPE-38	Custom field value	The "Sprint" custom field is not supported via migration. The value for this issue will not be migrated.	If you require this field value, use a csv import to update the issues post migration. See the 'Adding additional entities with CSV' section in this document: https://confluence.atlassian.com/cloud/what-gets-migrated-with-the-jira-cloud-migration-assistant-993925216.html

Workaround

Ignore the message in post report if the sprint of ticket is set in cloud side.