Link tasks to their restarts

Closes #1711 (closed)

arkindex/documents/api/ml.py

@@ -440,7 +440,7 @@ class ManageClassificationsSelection(SelectionMixin, CorpusACLMixin, CreateAPIVi
         mode = serializer.validated_data["mode"]
         if mode == ClassificationMode.Create:
             return self.create(corpus, request, *args, **kwargs)
-        elif mode == ClassificationMode.Validate:
+        if mode == ClassificationMode.Validate:
             elements = self.get_selection(corpus.id)
             Classification.objects.filter(
                 element__in=elements,