title: Flask admin , update a column after_model_change not working
body: <p>I have successfully overridden <code>on_model_change</code> in flask but when I try to do the same for <code>after_model_change</code> it does nothing , how to make changes to model after model changes ?</p>
  
  <pre><code>Class CustomAdminView(ModelView):  # pylint: disable=no-init
  
      #works fine and udpates the column
      def on_model_change(self, form, model, is_created):
          curr_user = getpass.getuser()
          model.updatedby = curr_user
  
      #does nothing to the model
      def after_model_change(self, form, model, is_created):
          current_remarks= model.remarks
          model.rhistory = f'changes made : {current_remarks}'
  </code></pre>
  
  <p>What I am doing is get the current remarks and update it to the history , but I can get the remarks column data after only it has been updated to the model
  If its not possible to do this in make changes after model has been updated ,Can I get the value of the the remarks which user is entering so that I can update it during model update.</p>