title: CK editor image uploading is not working in production with rails 5 app + carrierwave
body: <p>I am working with CK editor and after deploying I'm not able to upload any images but it was working in development. I get this error "image source url is missing" and here is my config.js file :</p>
  
  <p>I found a lot having the same error but no one answered why this is happening so should I migrate to another editor or what?!</p>
  
  <p><a href="https://i.stack.imgur.com/X3xBK.png" rel="nofollow noreferrer">config.js</a></p>
  
  <pre><code>I, [2018-02-02T12:48:12.886841 #16570]  INFO -- : [5a150ff6-afb3-4f98-a1cb-c954703b971d]   Parameters: {"upload"=&gt;#&lt;ActionDispatch::Http::UploadedFile:0x00007f51110b4668 @tempfile=#&lt;Tempfile:/tmp/RackMultipart20180202-16570-1g62x7e.jpg&gt;, @original_filename="ibrahim.jpg", @content_type="image/jpeg", @headers="Content-Disposition: form-data; name=\"upload\"; filename=\"ibrahim.jpg\"\r\nContent-Type: image/jpeg\r\n"&gt;, "ckCsrfToken"=&gt;"7n2JrWACJV1ceGDYnu1SUaY1p9iWr0Q4P0b40nQv", "CKEditor"=&gt;"post_content", "CKEditorFuncNum"=&gt;"1", "langCode"=&gt;"en"}
      I, [2018-02-02T12:48:12.892512 #16570]  INFO -- : [5a150ff6-afb3-4f98-a1cb-c954703b971d] Completed 401 Unauthorized in 6ms (ActiveRecord: 0.0ms)
      F, [2018-02-02T12:48:12.895003 #16570] FATAL -- : [5a150ff6-afb3-4f98-a1cb-c954703b971d]
      F, [2018-02-02T12:48:12.895093 #16570] FATAL -- : [5a150ff6-afb3-4f98-a1cb-c954703b971d] MiniMagick::Error (ImageMagick/GraphicsMagick is not installed):
      F, [2018-02-02T12:48:12.895128 #16570] FATAL -- : [5a150ff6-afb3-4f98-a1cb-c954703b971d]
      F, [2018-02-02T12:48:12.895216 #16570] FATAL -- : [5a150ff6-afb3-4f98-a1cb-c954703b971d] mini_magick (4.8.0) lib/mini_magick/configuration.rb:127:in `cli'
      [5a150ff6-afb3-4f98-a1cb-c954703b971d] mini_magick (4.8.0) lib/mini_magick.rb:38:in `graphicsmagick?'
      [5a150ff6-afb3-4f98-a1cb-c954703b971d] mini_magick (4.8.0) lib/mini_magick/tool.rb:126:in `executable'
      [5a150ff6-afb3-4f98-a1cb-c954703b971d] mini_magick (4.8.0) lib/mini_magick/tool.rb:110:in `command'
  </code></pre>