Add missing rpc.shutdown() (#44417)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/44417
Test Plan: Imported from OSS
Reviewed By: lw
Differential Revision: D23626208
Pulled By: mrshenli
fbshipit-source-id: 4ff8cad0e1193f99518804c21c9dd26ae718f4eb
