Hoppers dont suck empty buckets out of furnaces

When i was using and autosmelter i built powered by lava, the products were being sucked out by hoppers but the empty buckets were not. I am not sure if this was intended, but it would be great to be put back in to the game.

**it wouldnt let me submit it under 14w30c so i had to put version 14w32a i am not sure if it is an effected version though**