rest client: Expect context timeouts for locks (#10782)

Add option for rest clients to not mark a remote offline for context timeouts.

This can be used if context timeouts are expected on the call.

cmd/storage-rest-client.go

@@ -42,7 +42,7 @@ func isNetworkError(err error) bool {
 		return false
 	}
 	if nerr, ok := err.(*rest.NetworkError); ok {
-		return xnet.IsNetworkOrHostDown(nerr.Err)
+		return xnet.IsNetworkOrHostDown(nerr.Err, false)
 	}
 	return false
 }