message: Fix spec comment
diff: @@ -497,6 +497,7 @@ where
  //~ 1. Sample $\gamma$ with the Fq-Sponge.
  let gamma = fq_sponge.challenge();
  + //~ 1. If using lookup:
  if let Some(lcs) = &index.cs.lookup_constraint_system {
  //~~ - Compute the lookup aggregation polynomial.
  let joint_lookup_table_d8 = lookup_context.joint_lookup_table_d8.as_ref().unwrap();
  