message: follow_me: don't mess with cookie after reset
  The cookie should only be set to nullptr after a remove_call_every but
  not after a reset_call_every!
diff: @@ -145,7 +145,6 @@ FollowMe::Result FollowMeImpl::set_target_location(const FollowMe::TargetLocatio
  // If set already, reschedule it.
  if (_target_location_cookie) {
  _parent->reset_call_every(_target_location_cookie);
  - _target_location_cookie = nullptr;
  } else {
  // Register now for sending in the next cycle.
  _parent->add_call_every(
  