fixbug: kl-tabs设置selected属性报错

[jabbla]

<kl-tabs on-change={this.tabChange($event)} selected={{key: 1}}>
    <kl-tab title="Tab1" key=0>Content1</kl-tab>
    <kl-tab title="Tab2" key=1>Content2</kl-tab>
</kl-tabs>

报错：can't read 'key' of undefined.