update image

.devcontainer/devcontainer.json

@@ -14,5 +14,5 @@
     3000,
     9944
   ],
-  "image": "paritytech/substrate-playground-template-node-template:sha-8f769db"
+  "image": "paritytech/substrate-playground-template-node-template:sha-55f7ff5"
 }