Update src/modules/musig/session_impl.h

Co-authored-by: Elliott Jin <4276679+robot-dreams@users.noreply.github.com>

src/modules/musig/session_impl.h

@@ -702,7 +702,7 @@ int secp256k1_musig_partial_sig_verify(const secp256k1_context* ctx, const secp2
      *           = d_tweak*d_agg*d[i]*P[i]
      *           = d_tweak*d_agg*|P[i]|
      *
-     * The if condition is below is true whenever d_tweak*d_agg is
+     * The if condition below is true whenever d_tweak*d_agg is
      * negative (again, see the explanation in musig_partial_sign). In
      * this case, the verifier negates e which will have the same end
      * result as negating |P[i]|, since they are multiplied later anyway.