the problem of use HintShardingStrategy in version 4.0.1

[xinghh100-githhub]

When I use HintShardingStrategy in version 4.0.1, I actually return to UnicastRoutingEngine after executing RoutingEngineFactory#newInstance, this problem does not exist in 4.0.0-RC2.

The code usage example is as follows：

// config sharding rule
ShardingRuleConfiguration shardingRuleConfig = new ShardingRuleConfiguration();
shardingRuleConfig.setDefaultDatabaseShardingStrategyConfig(
new HintShardingStrategyConfiguration(new MyShardingAlgorithm())
);
shardingRuleConfig.setDefaultTableShardingStrategyConfig(
new NoneShardingStrategyConfiguration()
);

// use hint
hintManager.setDatabaseShardingValue (db);