adjust tester_helper to make multi-instance multi-thread work
adjust tester_helper to make multi-instance multi-thread work

test=develop

tensor-tang/Paddle,tensor-tang/Paddle,luotao1/Paddle,chengduoZH/Paddle,PaddlePaddle/Paddle,luotao1/Paddle,baidu/Paddle,tensor-tang/Paddle,PaddlePaddle/Paddle,luotao1/Paddle,PaddlePaddle/Paddle,luotao1/Paddle,chengduoZH/Paddle,chengduoZH/Paddle,chengduoZH/Paddle,baidu/Paddle,PaddlePaddle/Paddle,PaddlePaddle/Paddle,baidu/Paddle,tensor-tang/Paddle,luotao1/Paddle,baidu/Paddle,PaddlePaddle/Paddle,chengduoZH/Paddle,tensor-tang/Paddle,PaddlePaddle/Paddle,luotao1/Paddle,luotao1/Paddle,baidu/Paddle