Removed png vcodec from thumbnailing.
Removed png vcodec from thumbnailing.

tmrwbo/infinity-next,infinity-next/infinity-next,infinity-next/infinity-next,nextchan/infinity-next,interjection/infinity-next,tmrwbo/infinity-next,infinity-next/infinity-next,nextchan/infinity-next,nextchan/infinity-next,interjection/infinity-next,interjection/infinity-next,tmrwbo/infinity-next,nextchan/infinity-next