fix unit test of test/b5m-manager/t_product_db.cc : boost::unordered_set can not be enumerated with the guarantee of specified key order
fix unit test of test/b5m-manager/t_product_db.cc :
boost::unordered_set can not be enumerated with the guarantee of
specified key order

pombredanne/sf1r-lite,pombredanne/sf1r-lite,izenecloud/sf1r-lite,pombredanne/sf1r-lite,izenecloud/sf1r-ad-delivery,izenecloud/sf1r-ad-delivery,pombredanne/sf1r-lite,izenecloud/sf1r-lite,izenecloud/sf1r-lite,izenecloud/sf1r-ad-delivery,izenecloud/sf1r-ad-delivery,izenecloud/sf1r-lite,izenecloud/sf1r-lite,izenecloud/sf1r-ad-delivery,pombredanne/sf1r-lite