restrictions are now topo-sorted correctly

src/storm-dft/storage/dft/DFTBuilder.cpp

@@ -179,6 +179,12 @@ namespace storm {
                         topoVisit(c, visited, L);
                     }
                 }
+                if(n->isRestriction()) {
+                    visited[n] = topoSortColour::GREY;
+                    for (DFTElementPointer const& c : std::static_pointer_cast<DFTRestriction<ValueType>>(n)->children()) {
+                        topoVisit(c, visited, L);
+                    }
+                }
                 visited[n] = topoSortColour::BLACK;
                 L.push_back(n);
             }