Fix capnproto add_value_to_map overwriting all entries at index 0#634

liuzicheng1987 merged 1 commit intogetml:maingetml/reflect-cpp:mainfrom

lixin-wei:fix/capnproto-add-value-to-maplixin-wei/reflect-cpp:fix/capnproto-add-value-to-mapCopy head branch name to clipboard