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

detectron/utils/net.py

@@ -37,6 +37,7 @@ from detectron.utils.io import save_object
 import detectron.utils.c2 as c2_utils
 
 logger = logging.getLogger(__name__)
+logger.setLevel(logging.INFO)
 
 
 def initialize_from_weights_file(model, weights_file, broadcast=True):