Don't check for certificate when grabbing the chromosome file.
Don't check for certificate when grabbing the chromosome file.

closes chapmanb/bcbio-nextgen#1260

rchekaluk/cloudbiolinux,chapmanb/cloudbiolinux,chapmanb/cloudbiolinux,rchekaluk/cloudbiolinux,joemphilips/cloudbiolinux,chapmanb/cloudbiolinux,rchekaluk/cloudbiolinux,joemphilips/cloudbiolinux,chapmanb/cloudbiolinux,joemphilips/cloudbiolinux,rchekaluk/cloudbiolinux,joemphilips/cloudbiolinux