Prefetch the corpus on DataImports in the Django admin

arkindex/dataimport/admin.py

@@ -47,7 +47,7 @@ class DataImportAdmin(admin.ModelAdmin):
 
     def get_queryset(self, *args, **kwargs):
         return super().get_queryset(*args, **kwargs) \
-            .prefetch_related('workflow__tasks') \
+            .prefetch_related('workflow__tasks', 'corpus') \
             .annotate(last_run=Max('workflow__tasks__run'))