Fix same bug in Moller-Granlund implementation as occurred in invert_limb.
Fix same bug in Moller-Granlund implementation as occurred in invert_limb.

jpflori/flint2,dsroche/flint2,wbhart/flint2,jpflori/flint2,wbhart/flint2,fredrik-johansson/flint2,dsroche/flint2,fredrik-johansson/flint2,wbhart/flint2,jpflori/flint2,jpflori/flint2,dsroche/flint2,dsroche/flint2,fredrik-johansson/flint2