[AutoBalancer.cpp] fix typo of index

rtc/AutoBalancer/AutoBalancer.cpp

@@ -1158,7 +1158,7 @@ bool AutoBalancer::setFootStepsWithParam(const OpenHRP::AutoBalancerService::Foo
  for (size_t i = 0; i < fs_vec_list.size(); i++) {
  if (!(gg_is_walking && i == 0)) { // If initial footstep, e.g., not walking, pass user-defined footstep list. If walking, pass cdr footsteps in order to neglect initial double support leg.
  std::vector<step_node> tmp_fns;
- for (size_t j = 0; j < fs_vec_list.at(j).size(); j++) {
+ for (size_t j = 0; j < fs_vec_list.at(i).size(); j++) {
  tmp_fns.push_back(step_node(leg_name_vec_list[i][j], fs_vec_list[i][j], spss[i].sps[j].step_height, spss[i].sps[j].step_time, spss[i].sps[j].toe_angle, spss[i].sps[j].heel_angle));
  }
  fnsl.push_back(tmp_fns);