test: remove hardcoded message

message is platform and version dependent leading to test failures

Author: king-11

tests/test_clnrest.py

@@ -481,7 +481,7 @@ def test_websocket_upgrade_header(node_factory):
     @sio.event
     def message(data):
         notifications.append(data)
-    with pytest.raises(socketio.exceptions.ConnectionError, match="Unexpected response from server"):
+    with pytest.raises(socketio.exceptions.ConnectionError):
         sio.connect(base_url)
 
     time.sleep(2)