Use 404 rather than 500 for tile errors to prevent Bones from spewing console messages.
Use 404 rather than 500 for tile errors to prevent Bones from spewing console messages.

mbrukman/tilemill,Teino1978-Corp/Teino1978-Corp-tilemill,mbrukman/tilemill,tizzybec/tilemill,mbrukman/tilemill,Teino1978-Corp/Teino1978-Corp-tilemill,mbrukman/tilemill,tizzybec/tilemill,Zhao-Qi/tilemill,nyimbi/tilemill,tizzybec/tilemill,paulovieira/tilemill-clima,fxtentacle/tilemill,Zhao-Qi/tilemill,tilemill-project/tilemill,fxtentacle/tilemill,florianf/tileoven,florianf/tileoven,tizzybec/tilemill,nyimbi/tilemill,Teino1978-Corp/Teino1978-Corp-tilemill,florianf/tileoven,fxtentacle/tilemill,paulovieira/tilemill-clima,isaacs/tilemill,nyimbi/tilemill,MappingKat/tilemill,Teino1978-Corp/Teino1978-Corp-tilemill,MappingKat/tilemill,Zhao-Qi/tilemill,paulovieira/tilemill-clima,MappingKat/tilemill,fxtentacle/tilemill,nyimbi/tilemill,tilemill-project/tilemill,fxtentacle/tilemill,MappingKat/tilemill,paulovieira/tilemill-clima,tilemill-project/tilemill,mbrukman/tilemill,Zhao-Qi/tilemill,tizzybec/tilemill,MappingKat/tilemill,isaacs/tilemill,paulovieira/tilemill-clima,isaacs/tilemill,Teino1978-Corp/Teino1978-Corp-tilemill,Zhao-Qi/tilemill,nyimbi/tilemill