fix: exception in single tab mode; 🐛 #103

修复：单页签模式下的异常问问题；

src/layouts/tabs/TabsView.vue

@@ -70,7 +70,9 @@ export default {
   },
   mounted () {
     this.correctPageMinHeight(-this.tabsOffset)
+    if(this.multiPage){
       this.cachedKeys.push(this.$refs.tabContent.$vnode.key)
+    }
   },
   beforeDestroy() {
     window.removeEventListener('page:close', this.closePageListener)