update `-o modern` documentation for -h
update `-o modern` documentation for -h

bpzhang/memcached,memcached/memcached,gencer/memcached,elfchief/memcached,dormando/memcached,elfchief/memcached,guikcd/memcached,dormando/memcached,bpzhang/memcached,guikcd/memcached,elfchief/memcached,gencer/memcached,memcached/memcached,gencer/memcached,gencer/memcached,dormando/memcached,dormando/memcached,bpzhang/memcached,memcached/memcached,gencer/memcached,elfchief/memcached,guikcd/memcached,memcached/memcached,memcached/memcached,guikcd/memcached,guikcd/memcached,elfchief/memcached,bpzhang/memcached,dormando/memcached