new_workspace is mandatory

tracim/views/core_api/workspace_controller.py

             move_data.new_parent_id, content_type=ContentType.Any
         )
 
-        try:
-            new_workspace = request.candidate_workspace
-        except WorkspaceNotFoundInTracimRequest:
-            new_workspace = None
+        new_workspace = request.candidate_workspace
 
         with new_revision(
                 session=request.dbsession,