[prune] remove redundancy for main.py

Author: declmal

main.py

@@ -3,7 +3,7 @@
 
 sys.path.insert(0, "./python")
 
-from mrt.V3.utils import get_cfg_defaults, merge_cfg, override_cfg_args
+from mrt.V3.utils import merge_cfg, override_cfg_args
 from mrt.V3.execute import run
 from mrt.V3.utils import DOC as utils_doc
 from mrt.V3.prepare import DOC as prepare_doc
@@ -31,7 +31,6 @@ def complete_docs():
             "invalid length: {} of sys.argv: {}".format(
             len(sys.argv), sys.argv)
         yaml_file = sys.argv[1]
-        cfg = get_cfg_defaults()
         cfg = merge_cfg(yaml_file)
         cfg = override_cfg_args(cfg, sys.argv[2:])
         run(cfg)