fix redundant comma in hccl json

tutorials/source_en/advanced_use/distributed_training.md

@@ -72,7 +72,7 @@ The following uses the Ascend 910 AI processor as an example. The JSON configura
                 {"devices": [{"device_id": "4","device_ip": "192.1.27.7"}],"rank_id": "4","server_id": "10.155.111.140"},
                 {"devices": [{"device_id": "5","device_ip": "192.2.27.7"}],"rank_id": "5","server_id": "10.155.111.140"},
                 {"devices": [{"device_id": "6","device_ip": "192.3.27.7"}],"rank_id": "6","server_id": "10.155.111.140"},
-                {"devices": [{"device_id": "7","device_ip": "192.4.27.7"}],"rank_id": "7","server_id": "10.155.111.140"},
+                {"devices": [{"device_id": "7","device_ip": "192.4.27.7"}],"rank_id": "7","server_id": "10.155.111.140"}
                 ]
         }
     ],

tutorials/source_zh_cn/advanced_use/distributed_training.md

@@ -72,7 +72,7 @@
                 {"devices": [{"device_id": "4","device_ip": "192.1.27.7"}],"rank_id": "4","server_id": "10.155.111.140"},
                 {"devices": [{"device_id": "5","device_ip": "192.2.27.7"}],"rank_id": "5","server_id": "10.155.111.140"},
                 {"devices": [{"device_id": "6","device_ip": "192.3.27.7"}],"rank_id": "6","server_id": "10.155.111.140"},
-                {"devices": [{"device_id": "7","device_ip": "192.4.27.7"}],"rank_id": "7","server_id": "10.155.111.140"},
+                {"devices": [{"device_id": "7","device_ip": "192.4.27.7"}],"rank_id": "7","server_id": "10.155.111.140"}
                 ]
         }
     ],