fix error

lib/tasks/feeds_tasks.rake

@@ -11,7 +11,7 @@ namespace :feeds_module do
         req = Net::HTTP::Get.new(uri)
         http.request(req).body rescue ''
       end
-      File.open(File.join(feed_directory.to_s,self.feed_uid + ".json"),"w") do |file|
+      File.open(File.join(feed_directory.to_s,site_feed.feed_uid + ".json"),"w") do |file|
         res.force_encoding("utf-8")
         file.write(res)
       end