Revert "Update robots.txt for new preferred subdomain"
Revert "Update robots.txt for new preferred subdomain"

This reverts commit baff397266b36606472d372cf8d36b40f20d810b. It's
meant to start exploring a www-prefixed world, and not for immediate
merging.

yuki24/force,eessex/force,artsy/force,mzikherman/force,dblock/force,dblock/force,xtina-starr/force,xtina-starr/force,eessex/force,xtina-starr/force,erikdstock/force,damassi/force,damassi/force,yuki24/force,izakp/force,TribeMedia/force-public,kanaabe/force,artsy/force,artsy/force-public,artsy/force-public,cavvia/force-1,mzikherman/force,mzikherman/force,oxaudo/force,oxaudo/force,erikdstock/force,oxaudo/force,erikdstock/force,kanaabe/force,kanaabe/force,joeyAghion/force,joeyAghion/force,TribeMedia/force-public,izakp/force,erikdstock/force,artsy/force,yuki24/force,yuki24/force,izakp/force,anandaroop/force,dblock/force,damassi/force,kanaabe/force,anandaroop/force,cavvia/force-1,mzikherman/force,eessex/force,izakp/force,oxaudo/force,damassi/force,eessex/force,joeyAghion/force,cavvia/force-1,kanaabe/force,joeyAghion/force,anandaroop/force,anandaroop/force,xtina-starr/force,cavvia/force-1,artsy/force