merge with origin

Author: thelfer

bindings/python/mgis/fenics/nonlinear_problem.py

@@ -586,6 +586,8 @@ def __init__(self, u, material, quadrature_degree=2, bcs=None):
     def form(self, A, P, b, x):
         # this function is called before calling F or J
         self.update_constitutive_law()
+        if hasattr(self.solver, "update_pc"):
+            self.solver.update_pc()
         assemble_system(self.tangent_form,
                         self.residual,
                         A_tensor=A,