Call setup_logger in DefaultTrainer if logger is not enabled (facebookresearch/detectron2/issues/591)
Call setup_logger in DefaultTrainer if logger is not enabled (facebookresearch/detectron2/issues/591)

Summary: Pull Request resolved: https://github.com/fairinternal/detectron2/pull/359

Differential Revision: D19249015

Pulled By: ppwwyyxx

fbshipit-source-id: 838a27e9ceb7b009edc5f238239972834cde096e

facebookresearch/detectron2,facebookresearch/detectron2,facebookresearch/detectron2