Fix dgc bug.#16602

Merged

gongweibao merged 2 commits intoPaddlePaddle:developfrom

gongweibao:fixdgcclip

Apr 2, 2019

Commits on Apr 1, 2019

fix dgc bug test=develop
gongweibao
committed

Commits on Apr 2, 2019

modify h
gongweibao
committed