Reachability service occasionally fails

```python
Jul 19 09:22:42.251 [WARN] [petals.server.reachability._serve_with_probe:148] Reachability service failed: FileNotFoundError(2, 'No such file or directory')
Jul 19 09:22:42.252 [WARN] [petals.server.reachability._serve_with_probe:149] See detailed traceback below:
Traceback (most recent call last):
File "/storage/hdd1/jheuristic/exp/decentralized/borzunov/petals/src/petals/server/reachability.py", line 140, in _serve_with_probe
protocol.probe = await P2P.create(initial_peers, **STRIPPED_PROBE_ARGS)
File "/home/jheuristic/anaconda3/envs/py38_petals_borzunov/lib/python3.8/site-packages/hivemind/p2p/p2p_daemon.py", line 239, in create
self._client = await p2pclient.Client.create(
File "/home/jheuristic/anaconda3/envs/py38_petals_borzunov/lib/python3.8/site-packages/hivemind/p2p/p2p_daemon_bindings/p2pclient.py", line 41, in create
client.control = await ControlClient.create(
File "/home/jheuristic/anaconda3/envs/py38_petals_borzunov/lib/python3.8/site-packages/hivemind/p2p/p2p_daemon_bindings/control.py", line 135, in create
await control._ensure_persistent_conn()
File "/home/jheuristic/anaconda3/envs/py38_petals_borzunov/lib/python3.8/site-packages/hivemind/p2p/p2p_daemon_bindings/control.py", line 254, in _ensure_persistent_conn
reader, writer = await self.daemon_connector.open_persistent_connection()
File "/home/jheuristic/anaconda3/envs/py38_petals_borzunov/lib/python3.8/site-packages/hivemind/p2p/p2p_daemon_bindings/control.py", line 74, in open_persistent_connection
reader, writer = await self.open_connection()
File "/home/jheuristic/anaconda3/envs/py38_petals_borzunov/lib/python3.8/site-packages/hivemind/p2p/p2p_daemon_bindings/control.py", line 62, in open_connection
return await asyncio.open_unix_connection(control_path)
File "/home/jheuristic/anaconda3/envs/py38_petals_borzunov/lib/python3.8/asyncio/streams.py", line 111, in open_unix_connection
transport, _ = await loop.create_unix_connection(
File "uvloop/loop.pyx", line 2275, in create_unix_connection
File "uvloop/loop.pyx", line 2270, in uvloop.loop.Loop.create_unix_connection
FileNotFoundError: [Errno 2] No such file or directory
```