[2.x] 导航内置图标不生效

[heteng99]

navbar: [{ text: 'Home', link: '/', icon: 'reco-home' }]

像这样配置，没有图标出现
配置参考了 1.x 文档，2.x 好像没了？

[recoluan]

The icons are not the same as 1.x, please refer to here.