more helpful error message
more helpful error message

- directs people to set host to `0.0.0.0` (easier than knowing your ip address)

rbtrace/psiTurk,michaelpacer/psiTurk,NYUCCL/psiTurk,berkeley-cocosci/psiTurk,johnmcdonnell/psiTurk,suchow/psiTurk,NYUCCL/psiTurk,andyh616/psiTurk,pfeyz/psiTurk,johnmcdonnell/psiTurk,kachergis/psiTurk,pfeyz/psiTurk,suchow/psiTurk,mshvartsman/psiTurk,michaelpacer/psiTurk,michaelpacer/psiTurk,mshvartsman/psiTurk,kachergis/psiTurk,pfeyz/psiTurk,suchow/psiTurk,berkeley-cocosci/psiTurk,kachergis/psiTurk,rbtrace/psiTurk,andyh616/psiTurk,mshvartsman/psiTurk,johnmcdonnell/psiTurk,NYUCCL/psiTurk,andyh616/psiTurk,berkeley-cocosci/psiTurk,rbtrace/psiTurk