修复在下载一个模块的pdf文档时，未对字符串做转义导致pdf语法检查失败的问题
报错示例：{"page":null,"success":0,"data":null,"error":{"code":"E000001","message":"系统未知错误!「Unknow Error!」，提示：Invalid nested tag p found, expected closing tag br.，详细错误：com.itextpdf.tool.xml.exceptions.RuntimeWorkerException: Invalid nested tag p found, expected closing tag br.\r"},"others":null}