skipping the padding message (#3634)
skipping the padding message (#3634)

* skipping the padding message

* shorter version of condition

* generator agent sees the batch padding message

* using message function to check for padding
facebookresearch/ParlAI,facebookresearch/ParlAI,facebookresearch/ParlAI,facebookresearch/ParlAI,facebookresearch/ParlAI