[fix]  fix a bug that redis-rdb-keys may use too much memory when load, fixed.
[fix]  fix a bug that redis-rdb-keys may use too much memory when load, fixed.

zhongliangkang/redis2.8.17,zhongliangkang/redis2.8.17,zhongliangkang/redis2.8.17,zhongliangkang/redis2.8.17,zhongliangkang/redis2.8.17