Update test_all_gather_grad.py

Author: shuyingsunshine21

tests/utilities/test_all_gather_grad.py

@@ -13,7 +13,7 @@
 def setup_ddp(rank, world_size):
     """ Setup ddp enviroment """
     os.environ["MASTER_ADDR"] = "localhost"
-    os.environ["MASTER_PORT"] = "29501"
+    os.environ["MASTER_PORT"] = "8088"
 
     if torch.distributed.is_available() and sys.platform not in ("win32", "cygwin"):
         torch.distributed.init_process_group("gloo", rank=rank, world_size=world_size)