update src/admin/sys_data_done.php.

通过敏感字符过滤，修复了sys_data_done.php中存在的SQL注入漏洞。

Signed-off-by: 再遇雌鹿 <1937635949@qq.com>

src/admin/sys_data_done.php

@@ -100,6 +100,7 @@ if ($dopost == 'bak') {
         $fs = array();
         $bakStr = '';
         //分析表里的字段信息
+        $nowtable = str_replace("`", "", $nowtable);
         $dsql->GetTableFields($nowtable);
         $intable = "INSERT INTO `$nowtable` VALUES(";
         while ($r = $dsql->GetFieldObject()) {