rsync -- path-sanitizing bug that affects daemon mode if chroot is disabled

There is a path-sanitizing bug that affects daemon, but only if chroot is disabled. It does NOT affect the normal send/receive filenames that specify what files should be transferred (this is because these names happen to get sanitized twice, and thus the second call removes any lingering leading slash(es) that the first call left behind). It does affect certain option paths that cause auxilliary files to be read or written.