Uppercase model filenames enabled (#2890)

utils/google_utils.py

@@ -18,7 +18,7 @@ def gsutil_getsize(url=''):
 
 def attempt_download(file, repo='ultralytics/yolov5'):
     # Attempt file download if does not exist
-    file = Path(str(file).strip().replace("'", '').lower())
+    file = Path(str(file).strip().replace("'", ''))
 
     if not file.exists():
         try: