Obstacles in the MonotoneMgStep are now protected

dune/solvers/solvers/trustregionsolver.cc

@@ -25,7 +25,7 @@ void TrustRegionSolver<ProblemType,VectorType,MatrixType>::solve()
         for (int j=0; j<blocksize; j++)
             trustRegionObstacles[i][j] = { -initialRadius_, initialRadius_ };
 
-    mgStep->obstacles_ = &trustRegionObstacles;
+    mgStep->setObstacles(trustRegionObstacles);
 
     // /////////////////////////////////////////////////////
     //   Trust-Region Solver