message: [bugfix] List: add loading key to avoid render error
diff: @@ -117,7 +117,7 @@ export default sfc({
  <div class={bem()}>
  {this.slots()}
  {this.loading && (
  - <div class={bem('loading')}>
  + <div class={bem('loading')} key="loading">
  {this.slots('loading') || [
  <Loading class={bem('loading-icon')} />,
  <span class={bem('loading-text')}>{this.loadingText || t('loading')}</span>
  