Enable test_multi_py_udf_remote in rpc_test.py
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/29471
Test Plan: Imported from OSS
Differential Revision: D18404819
Pulled By: mrshenli
fbshipit-source-id: 8cf3e32d7980e34c48bfd8fb61cfd9a0acc9bd46
