Remove source field from creation endpoints

arkindex/documents/api/ml.py

@@ -377,7 +377,7 @@ class ClassificationCreate(CreateAPIView):
     }
 
     def perform_create(self, serializer):
-        if serializer.validated_data['source'] and serializer.validated_data['source'].slug == 'manual':
+        if serializer.validated_data['worker_version'] is None:
             # A manual classification is immediately valid
             serializer.save(
                 moderator=self.request.user,