[la.solver.istl] also catch FMatrixError

dune/xt/la/solver/istl.hh

@@ -347,6 +347,10 @@ public:
       DUNE_THROW(Exceptions::linear_solver_failed,
                  "The dune-istl backend reported: " << e.what() << "Those were the given options:\n\n"
                                                     << opts);
+    } catch (FMatrixError& e) {
+      DUNE_THROW(Exceptions::linear_solver_failed,
+                 "The dune-istl backend reported: " << e.what() << "Those were the given options:\n\n"
+                                                    << opts);
     }
   } // ... apply(...)