Issue Summary

This is reproducible on Data Center: (yes)

Steps to Reproduce

1. Create space on Confluence Cloud call it Product Management and the space key will be PM.
2. Then rename the Spacekey on the cloud from the PM to PM2.
   • steps to rename space key https://community.atlassian.com/t5/Confluence-Cloud-Admins-articles/Introducing-edit-space-key-all-editions/ba-p/2851665#M516 
3. Then on Confluence DC create a space with name Product Management with Space key PM.
4. Create a migration plan on server and to migrate this space with Space key PM.
5. Then preflight check will run you get a duplicate space key message as shown in the sample screenshot below:

Expected Results

• The CCMA should be able should the correct spacekey alias with which we have conflict.
• And we would be able to remove the conflicting space from the migration plan. 

Actual Results

• We get to know the conflicting space key/name in UI.
• Also, we cannot remove the space from the migration plan.

Workaround

• Contact Atlassian Support to get the alias of the spacekey from the cloud DB.
• Then on source server rename spacekey following the steps in the article:
  https://confluence.atlassian.com/confkb/how-to-copy-or-rename-a-space-in-confluence-169578.html