Cherry pick 1.4/ptb fix#16607

Merged

JiabinYang merged 3 commits intoPaddlePaddle:release/1.4from

JiabinYang:cherry_pick_1.4/ptb_fix

Apr 8, 2019

Commits on Apr 1, 2019

Commits on Apr 2, 2019

test=release/1.4, fix ci failed error
JiabinYang
committed