fix(nested_select): Don't add attr_accessor if field exists
fix(nested_select): Don't add attr_accessor if field exists

mabdelfattah/activeadmin_addons,siutin/activeadmin_addons,mabdelfattah/activeadmin_addons,halilim/activeadmin_addons,halilim/activeadmin_addons,platanus/activeadmin_addons,halilim/activeadmin_addons,siutin/activeadmin_addons,platanus/activeadmin_addons,mabdelfattah/activeadmin_addons,platanus/activeadmin_addons,mabdelfattah/activeadmin_addons,platanus/activeadmin_addons,siutin/activeadmin_addons