Update app.py

app.py

@@ -47,7 +47,7 @@ async def echo(websocket):
                 if jm["token"] not in b.keys():
                     b.update({jm["token"]: []})
                 b[jm["token"]].append(jm["data"])
-                json.dump(b, open("b.json"))
+                json.dump(b, open("b.json"), "w")
         except Exception as e:
             print(e)
             print(message)