Dynare++: fix check for QZ eigenvalue criterium

The criterium was previously incorrectly applied to the square absolute value
of eigenvalues. Rather apply it to the absolute value itself (as now done in
Dynare).

Ref #1632

(manually cherry picked from commit 8ebcd7ca)

dynare++/kord/first_order.cweb

@@ -22,7 +22,7 @@ to select (return true) the pairs for which $\alpha<\beta$.
 @<|order_eigs| function code@>=
 lapack_int order_eigs(const double* alphar, const double* alphai, const double* beta)
 {
-	return (*alphar * *alphar + *alphai * *alphai < *beta * *beta * qz_criterium);
+	return (*alphar * *alphar + *alphai * *alphai < *beta * *beta * qz_criterium * qz_criterium);
 }