Merge pull request #2195 from yangdan8/patch-4

Update table.vue  解决tabs切换时,tab中的table调试时控制台报$el undefined的问题

src/components/table/table.vue

@@ -345,6 +345,7 @@
                         this.tableWidth = parseInt(getStyle(this.$el, 'width')) - 1;
                     }
                     this.columnsWidth = {};
+                    if (!this.$refs.tbody) return;
                     this.$nextTick(() => {
                         let columnsWidth = {};
                         let autoWidthIndex = -1;