Set logging level correctly in utils/net.py
Set logging level correctly in utils/net.py

Summary:
AFAIK, this is what the rest of the codebase does. I don't want to
see logger.debug() messages show up during normal runs.

Differential Revision: D9071531

fbshipit-source-id: 4ac5ef57ee47bf958e35d723c379f695554f0ef0

facebookresearch/Detectron,facebookresearch/Detectron,facebookresearch/Detectron