In System api, default_environment is still being retrieved from the User (which is no longer being defined there). This fix obtains the environment from the user's default_organization.
Related issues
Bug #7025: on content-host create, default_environment undefined for user
Fixes #7025 - replace default_environment in sys
In System api, default_environment is still being retrieved from the
User (which is no longer being defined there). This fix obtains the
environment from the user's default_organization.