修复ueditor demo关闭tab后再打开无法显示bug

src/views/demo/ueditor.vue

      </div>
    </el-alert>
    <script id="J_ueditorBox" class="ueditor-box" type="text/plain" style="width: 100%; height: 260px;">hello world!</script>
    <script :id="ueId" class="ueditor-box" type="text/plain" style="width: 100%; height: 260px;">hello world!</script>
    
    <!-- 获取内容 -->
    <p><el-button @click="getContent()">获得内容</el-button></p>
    data () {
      return {
        ue: null,
        ueId: `J_ueditorBox_${new Date().getTime()}`,
        ueContent: '',
        dialogVisible: false
      }
    },
    mounted () {
      this.ue = ueditor.getEditor('J_ueditorBox', {
      this.ue = ueditor.getEditor(this.ueId, {
        // serverUrl: '', // 服务器统一请求接口路径
        zIndex: 3000
      })