- [x] I have searched the [issues](https://github.com/apache/dubbo/issues) of this repository and believe that this is not a duplicate.
- [x] I have checked the [FAQ](https://github.com/apache/dubbo/blob/master/FAQ.md) of this repository and believe that this is not a duplicate.

Because of TripleClientHandler working in a new thread, The line `url.getServiceMode`  doesn't work in TripleClientHandler with InstanceAddressURL when we try to use application-service-discovery.
```java
// => org.apache.dubbo.rpc.protocol.tri.TripleClientHandler#writeRequest
private void writeRequest(ChannelHandlerContext ctx, final Request req, final ChannelPromise promise) {
    final RpcInvocation inv = (RpcInvocation) req.getData();
    final URL url = inv.getInvoker().getUrl();
    // Here will throw NPE
    ConsumerModel consumerModel = (ConsumerModel) url.getServiceModel();
    // ......
}
```

See InstanceAddressURL:
```java
// => org.apache.dubbo.registry.client.InstanceAddressURL#getServiceModel
public ServiceModel getServiceModel() {
    return RpcContext.getServiceContext().getConsumerUrl().getServiceModel();
}

// => org.apache.dubbo.rpc.RpcContext
private static final InternalThreadLocal<RpcServiceContext> SERVICE_CONTEXT = new InternalThreadLocal<RpcServiceContext>() {
    @Override
    protected RpcServiceContext initialValue() {
        return new RpcServiceContext();
    }
};
```

} catch (TimeoutException e) {
            throw new RpcException(RpcException.TIMEOUT_EXCEPTION,
                    "Invoke remote method timeout. method: " + invocation.getMethodName() + ", provider: " + getUrl()
                            + ", cause: " + e.getMessage(), e);
        } catch (RemotingException e) {
            throw new RpcException(RpcException.NETWORK_EXCEPTION,
                    "Failed to invoke remote method: " + invocation.getMethodName() + ", provider: " + getUrl()
                            + ", cause: " + e.getMessage(), e);
        }
    }
    @Override
    public boolean isAvailable() {
        if (!super.isAvailable()) {
            return false;
        }
        return connection.isAvailable();
    }
    @Override
    public void destroy() {
        
        
        
        if (!super.isDestroyed()) {
            
            destroyLock.lock();
            try {
                if (super.isDestroyed()) {
                    return;
                }
                super.destroy();