Replace obsolete URI.unescape with CGI.unescape

MIGRATING.md

@@ -260,7 +260,7 @@ namespace :organizations do
       # don't have an explicit file extension in the filename
       image = organization.logo_file_name
       ext = File.extname(image)
-      image_original = URI.unescape(image.gsub(ext, "_original#{ext}"))
+      image_original = CGI.unescape(image.gsub(ext, "_original#{ext}"))
 
       # this url pattern can be changed to reflect whatever service you use
       logo_url = "https://s3.amazonaws.com/xxxxx/organizations/#{organization.id}/#{image_original}"