fixed pressure bnd in jacobi

src/elasticity/assemble/LagrangeElasticity.cpp

@@ -283,7 +283,7 @@ void LagrangeElasticity::Jacobi(const cell &c, const Vector &U, Matrix &A) const
             for (int j = 0; j < FE.NodalPoints(); ++j) {
               for (int l = 0; l < c.dim(); ++l) {
                 auto u_jl = FE.VectorValue(q, j, l);
-                auto F_jl = E.VectorGradient(q, j, l);
+                auto F_jl = FE.VectorGradient(q, j, l);
                 A_c(i, j, k, l) -= w * (localPressure) * (Cross(F, F_jl) * N) * u_ik;
               }
             }