Merge pull request discourse#1053 from vipulnsward/remove_var

Remove unused var.

Author: eviltrout

app/models/post_analyzer.rb

@@ -18,7 +18,6 @@ def cook(*args)
 
     # If we have any of the oneboxes in the cache, throw them in right away, don't
     # wait for the post processor.
-    dirty = false
     result = Oneboxer.apply(cooked) do |url, elem|
       Oneboxer.invalidate(url) if args.last[:invalidate_oneboxes]
       Oneboxer.onebox url