[optimize.sh] fixed error when side 1 (c-side) is rational
[optimize.sh] fixed error when side 1 (c-side) is rational

mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs