add download ceph images in bsroot.sh
add download ceph images in bsroot.sh

JunfeiYang/sextant,zhengbo0/sextant,JunfeiYang/sextant,gaoyw1/sextant,JunfeiYang/sextant,k8sp/sextant,gaoyw1/sextant,k8sp/sextant,zhengbo0/sextant,zhengbo0/sextant,k8sp/sextant,gaoyw1/sextant,k8sp/sextant