Removed attribute

poisson/discrete/linear_problem.py

@@ -649,7 +649,6 @@ class LinearProblem(object):
         self.lhs_sparse = None
         self.rhs_sparse_mat = None
         self.rhs_vector_sparse = None
-        self.mumps_solver_obj = None
 
         self.points_input = None
         self.points_output = None