Commit 0d8887652d ("qa/tasks/cram: use suite_repo repository for all
cram jobs") removed hardcoded git.ceph.com links, but as it turned out
it is still used for nightlies. There is no good way to accommodate
the different URL schemes, so let's get rid of URLs altogether.
Fixes: https://tracker.ceph.com/issues/27211
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>