message: Fix warning from branch warning_fix_vincent
diff: @@ -101,7 +101,9 @@ class Simplex_tree_boundary_simplex_iterator : public boost::iterator_facade<
  // any end() iterator
  explicit Simplex_tree_boundary_simplex_iterator(SimplexTree * st)
  - : sib_(nullptr),
  + : last_(st->null_vertex()),
  + next_(st->null_vertex()),
  + sib_(nullptr),
  sh_(st->null_simplex()),
  st_(st) {
  }
  @@ -109,7 +111,9 @@ class Simplex_tree_boundary_simplex_iterator : public boost::iterator_facade<
  template<class SimplexHandle>
  Simplex_tree_boundary_simplex_iterator(SimplexTree * st, SimplexHandle sh)
  : last_(sh->first),
  + next_(st->null_vertex()),
  sib_(nullptr),
  + sh_(st->null_simplex()),
  st_(st) {
  // Only check once at the beginning instead of for every increment, as this is expensive.
  if (SimplexTree::Options::contiguous_vertices)
  @@ -123,9 +127,7 @@ class Simplex_tree_boundary_simplex_iterator : public boost::iterator_facade<
  sh_ = sib_->members_.begin()+next_;
  else
  sh_ = sib_->find(next_);
  - } else {
  - sh_ = st->null_simplex();
  - } // vertex: == end()
  + }
  }
  private:
  