Trying to add 'lineheight' pluggin

[Frank]

I am trying to add the lineheight plugin, i created my config.js and added :
config.extraPlugins = 'lineheight,richcombo,floatpanel,panel,listblock,button';.
i also initialised the ckeditor as per the instruction:

Ckeditor.setup do |config|
  require 'ckeditor/orm/active_record'
  config.js_config_url = 'ckeditor/config.js'
  config.cdn_url = "//cdn.ckeditor.com/4.7.0/standard/ckeditor.js"
  config.image_file_types = %w[jpg jpeg png gif tiff]
  config.attachment_file_types = %w[doc docx xls odt ods pdf rar zip tar tar.gz swf]
  puts(config)
end

But for some reason, ckeditor is looking for the lineheight plugin through the CDN insead of
app/assets/javascripts/ckeditor/plugins/lineheight/plugin.js

and it returns the error :

Uncaught Error: [CKEDITOR.resourceManager.load] Resource name "lineheight" was not found at "http://cdn.ckeditor.com/4.7.0/standard/plugins/lineheight/plugin.js?t=H4PG".
    at CKEDITOR.resourceManager.<anonymous> (ckeditor.js:251:80)

How can i fix so it get the plugin from the plugin.js inside the right folder please ?

[Patrick A. Karjala]

Which version of the ckeditor gem are you using?