set matching_heuristics as True by default

Summary: Set matching_heuristics as True by default as detection methods usually add some prefix (e.g. "backbone.") for pre-trained weights

Reviewed By: wat3rBro

Differential Revision: D35519683

fbshipit-source-id: 77d3d53d556757c8f45b5ea3c2edec239e70a7a0

Author: lyttonhao

detectron2/checkpoint/detection_checkpoint.py

@@ -88,6 +88,7 @@ def _load_file(self, filename):
         loaded = super()._load_file(filename)  # load native pth checkpoint
         if "model" not in loaded:
             loaded = {"model": loaded}
+        loaded["matching_heuristics"] = True
         return loaded
 
     def _load_model(self, checkpoint):