When editing CT draft is edited instead of published version.

Steps

1. Create new CTG
2. Create new CT.
3. Add 1 text line field.
4. Save
5. Edit the CT.
6. Delete the text line field.
7. Discard changes
8. Check the CT preview (click on it). [text line field is still displayed]
9. Edit the CT and verify displayed fields.

Actual: No fields are displayed, last draft is being edited.
Expected: Text line field is displayed, the published version is being edited.