Revert D29154971: Training resnext with msuru_suru_union and ig_msuru_suru_union datasets
Test Plan: revert-hammer
Differential Revision:
D29154971 (https://github.com/pytorch/pytorch/commit/9f68f93aca0f4cc9726ef697db13715f699fb234)
Original commit changeset: d534d830020f
fbshipit-source-id: a3d16acc8e6b66a6010b501c28dbe295f573bc86
