Fixes typo in LazyConfigs tutorial
Fixes typo in LazyConfigs tutorial

Summary:
Fix for https://github.com/facebookresearch/detectron2/issues/3503

Pull Request resolved: https://github.com/facebookresearch/detectron2/pull/3504

Reviewed By: sstsai-adl

Differential Revision: D31128158

Pulled By: ppwwyyxx

fbshipit-source-id: 6b5a2b10d95b0cf567a940d0fcece3cb02685976

facebookresearch/detectron2,facebookresearch/detectron2,facebookresearch/detectron2