Allow empty net type (#19154)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/19154
I recently saw some weird workflow error due to empty but set net_type. Maybe we should just fallback to simple net in this case.
Reviewed By: dzhulgakov
Differential Revision: D14890072
fbshipit-source-id: 4e9edf8232298000713bebb0bfdec61e9c5df17d
