Fix Production admin order bug

production/admin.py

@@ -27,7 +27,7 @@ admin.site.register(ProductionStream, ProductionStreamAdmin)
 
 class ProductionEventAdminForm(forms.ModelForm):
     stream = forms.ModelChoiceField(
-        queryset=ProductionStream.objects.order_by('-submission.arxiv_identifier_w_vn_nr'))
+        queryset=ProductionStream.objects.order_by('-submission__arxiv_identifier_w_vn_nr'))
 
     class Meta:
         model = ProductionEvent