```
2024-06-24T05:14:14.9939033Z > l1.rpc.call('dev-feerate', [l2.info['id'], rate - 5])
2024-06-24T05:14:14.9939354Z
2024-06-24T05:14:14.9939466Z tests/test_connection.py:3439:
...
2024-06-24T05:14:14.9967617Z > raise RpcError(method, payload, resp['error'])
2024-06-24T05:14:14.9968833Z E pyln.client.lightning.RpcError: RPC call failed: method: dev-feerate, payload: ['022d223620a359a47ff7f7ac447c85c46c923da53389221a0054c11c1e3ca31d59', 2290], error: {'code': -1, 'message': 'Peer bad state'}
```
The disconnect can actually take a while: wait for both sides to
believe they're reconnected. Also wait a little to make sure the
feerate change doesn't create a bad signature.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>