Retry awscli install. (#21383)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/21383
ghimport-source-id: e518a4f8bf498694b6d504b8a695c5f11e7c681f
Differential Revision: D15664738
Pulled By: ezyang
fbshipit-source-id: d645db505de906e65c057f0d6964b5ce0fb6ff52
