Move task import in MultilingualTransformer to fix circular dependencies
Move task import in MultilingualTransformer to fix circular dependencies

Summary: Pull Request resolved: https://github.com/fairinternal/fairseq-py/pull/687

Differential Revision: D16005399

Pulled By: myleott

fbshipit-source-id: bf099c17e2095394acc452e9abcb4ee04afd0426

pytorch/fairseq,pytorch/fairseq,pytorch/fairseq