How to hide class information when working with Rails activeadmin

I am uploading images using activeadmin and paperclip.

camp.rb (activeadmin file)

f.input :photo1, :as => :file, :label => 'Foto1', :hint => f.template.image_tag(f.object.photo1.url(:small))

      

        
        
        
      

    

everything works fine, but i can see information about the class

<ol>#<#<Class:0x007fcf21d8dc48>:0x007fcf22f38f60>
  <li class="file input optional"    id="camp_photo1_input">
    <label class="label" for="camp_photo1">Foto1</label>
    <input id="camp_photo1" name="camp[photo1]" type="file">
    <p class="inline-hints">
      <img alt="Unium" src="/assets/camps/1/small/unium.jpg?1417540812">
    </p>
  </li>
</ol>

      

        
        
        
      

    

How to hide # <#: 0x007fcf22f38f60>? Thanks for the help!