Don't break Websocket connection on BlockingIO & like error

Previous commit catcher wider exception in WebsocketWrapper (OSError),
which include temporary error like BlockingIOError, SSLWantReadError...
This caused Websocket connection to break and cause client reconnection
when it should only cause a later retry.
Revert to catching previous ConnectionError, which should be fine, other
fatal error like SSLEOFError that might happen would still be catched
by caller (_sock_recv) which will take care of closing the websocket connection

src/paho/mqtt/client.py

@@ -4296,7 +4296,7 @@ def _recv_impl(self, length: int) -> bytes:
             else:
                 raise BlockingIOError
 
-        except OSError:
+        except ConnectionError:
             self.connected = False
             return b''