arch_content.txt: use open university link to FAC paper
arch_content.txt: use open university link to FAC paper

jonfoster/pyxb-upstream-mirror,CantemoInternal/pyxb,jonfoster/pyxb2,jonfoster/pyxb-upstream-mirror,pabigot/pyxb,jonfoster/pyxb2,CantemoInternal/pyxb,jonfoster/pyxb-upstream-mirror,jonfoster/pyxb2,balanced/PyXB,balanced/PyXB,pabigot/pyxb,CantemoInternal/pyxb,balanced/PyXB