Cannot import a repository with a "team" owner (BB-10316)

When trying to import a repo, the import fails if the "owner" is set to a team entity.

For example, I have a team called "myorg", and when I import, I select "myorg" as the Owner in the "New Repository" section. I think run the import, and it fails, with the following entry:

13:21:00 fatal: No existing author found with 'myorg'

However, I can import with my own user account as then owner, and then transfer ownership to 'myorg' after the import has finished.

This occurred during a subversion (on-demand instance) to bitbucket git import.