s/repo.continuum.io/repo.anaconda.com/ (#36233)
Summary:
Followup after https://github.com/pytorch/pytorch/pull/36201
Per https://github.com/conda/conda/issues/6886 `repo.anaconda.com` should have been used since Feb 2019
Pull Request resolved: https://github.com/pytorch/pytorch/pull/36233
Test Plan: CI
Differential Revision: D20920706
Pulled By: malfet
fbshipit-source-id: 1a9027e60df4de21111731d7fbda28c02846b417
