控制element表格禁用选择

当接口数据中不包含media.mediamgr.groupDelete这个参数的时候无法进行选择，多选操作当前项被禁用；

官方参数：selectable

  

      <el-table
            :data="tableData"
            @selection-change="handleSelectionChange"
        >
            <el-table-column
                :selectable="selectable"
                type="selection"
                fixed
            ></el-table-column>
       </el-table>

      /**
         * 判断右侧表格数据是否能够被勾选删除
         */
        selectable(row, index) {
            if (row.childactionlist.indexOf('media.mediamgr.groupDelete') > -1) {
                return true;
            } else {
                return false;
            }
        },