refactor(Tabs): 删除 css height:initial 属性

height 属性没有继承性，设置为 initial 和不写是等价的

Author: juzi214032

src/tabs/index.less

@@ -119,12 +119,6 @@
   transition: transform 0.3s cubic-bezier(0.645, 0.045, 0.355, 1);
 }
 
-.l-tabs-vertical {
-  .l-tabpanel-swiper {
-    height: initial;
-  }
-}
-
 .l-placement-top .l-tabpanel-content,
 .l-placement-bottom .l-tabpanel-content {
   width: 100%;