Update main.py

Hello Yohsuke, the way the autotune argument was written did not permit it to deactivate it, i.e. the flag was always set to true.  Can you please accept this change and include them in the new docker so I can actually deactivate the autotune.

Thank you.

main.py

@@ -109,8 +109,7 @@ def get_args():
         dest="autotune",
         action="store_true",
         required=False,
-        default=True,
-        help="Flag to autotune the parameters [default=True].",
+        help="Flag to autotune the parameters [default=False].",
     )
     optional.add_argument(
         "-ie",