title: Overriding can't assign mass-protected attributes
body: <p>I have fields that should not be accessible for anybody, so I can't just add these fields to attr_accessible. But also I have active admin which should have access to those fields. So far I tried next:</p>
  
  <pre><code>controller do
    def update
      org = Organization.find_by_id(params[:id])
      org.subscription.plan_id = params[:organization][:subscription_attributes][:plan_id]
      org.subscription.expires_at = params[:organization][:subscription_attributes][:expires_at]
      org.save
      super
    end
  end
  </code></pre>
  
  <p>But <code>super</code> still call update attributes on all params, not just ones that were changed. How can I exclude fields to be updated in super?</p>