[Enhancement] Remove unnecessary custom_import from test.py (#758)

tools/test.py

@@ -130,10 +130,7 @@ def main():
     if args.cfg_options is not None:
         cfg.merge_from_dict(args.cfg_options)
     setup_multi_processes(cfg)
-    # import modules from string list.
-    if cfg.get('custom_imports', None):
-        from mmcv.utils import import_modules_from_strings
-        import_modules_from_strings(**cfg['custom_imports'])
+
     # set cudnn_benchmark
     if cfg.get('cudnn_benchmark', False):
         torch.backends.cudnn.benchmark = True