don't set DEBUG=1 in py3.6-gcc5.4 CI build (#29491)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/29491
Setting DEBUG=1 causes tests to run super slow. There are two reasons
why you might do it:
1. Testing `#NDEBUG` stuff. We don't really use this macro.
2. https://github.com/pytorch/pytorch/issues/4119. This is valid,
but I would prefer to allow internal contbuilds to test this, as the
infra is better there.
Test Plan: Imported from OSS
Differential Revision: D18411635
Pulled By: suo
fbshipit-source-id: 54e1d0f9cddaa448cd2dd11fe263d5001845bdd8
