从soap服务器响应中删除文档类型声明DTD

Question

1. The response my webservice gives is not accepted by my (future) customer's system.
   1.1 Client receives "DTD encountered in SOAP context" error.
   1.1.1 IBM Knowledge Center

0x00030004 DTD encountered in SOAP context
Explanation:
An XML Firewall service has rejected a SOAP message because the message contained a DTD (Document Type Declaration). Such messages are not allowed by the SOAP standard.
Correct the problem by removing the DTD from the XML document or by reconfiguring the XML Firewall service to a non-soap parsing mode, such as "xml" or "unprocessed"-last option not possible because client side-. Administrator response: None Severity: error

1. So, I need to remove the DTD from the xml document.
   2.1 Problem is, we use a soap library that handle this for us. [PhpSoapServer][2]

2. SOAPUI get the response just fine

xml

<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ns1="http://www.uv.com/wsdl/VoucherService/xsd">
   <SOAP-ENV:Body>
      <ns1:GetLinkVoucherResponse>
         <url>https://u-v.io/OLaGsFr</url>
      </ns1:GetLinkVoucherResponse>
   </SOAP-ENV:Body>
</SOAP-ENV:Envelope>

and raw

HTTP/1.1 200 OK
Server: nginx/1.11.8
Content-Type: text/html; charset=UTF-8
Transfer-Encoding: chunked
Connection: keep-alive
Vary: Accept-Encoding
Access-Control-Allow-Origin: *
Access-Control-Allow-Headers: Content-Type, Access-Control-Allow-Headers,     Authorization, X-Requested-With
Cache-Control: no-cache
Date: Thu, 16 Mar 2017 15:48:36 GMT
Set-Cookie:      laravel_session=XXREMOVEDCHARg1NzVNSlE9PSIsInZhbHVlIjoiVHlJdVwvNUVDMm9uTEtkRjJRSWpRaFwvYjY5NlVuQW5LeHUwMThRbEZoYWY4TkTWFmOVJoalZ3RVNnZUtKRzYzSGxkN2N5UjgzXC9yZ09ST0E9PSIsIm1hYyI6ImZmNTQyMzIzZWQ1NTE3ZTk2ODM3ZWMwMGIzYmMyMDViNGQ0YThlOWNlNjY0MjJjODM0NWY4NmI0OTI3YjFhOTQifQ%3D%3D; expires=Thu, 16-  Mar-2017 17:48:36 GMT; Max-Age=7200;
path=/; HttpOnly
X-Frame-Options: SAMEORIGIN
X-XSS-Protection: 1; mode=block
X-Content-Type-Options: nosniff
Content-Encoding: gzip

<?xml version="1.0" encoding="UTF-8"?>
<SOAP-ENV:Envelope xmlns:SOAP-    ENV="http://schemas.xmlsoap.org/soap/envelope/"    xmlns:ns1="http://www.uv.com/wsdl/VoucherService/xsd"><SOAP-ENV:Body>       <ns1:GetLinkVoucherResponse><url>https://u-v.io/OLaGsFr</url>       </ns1:GetLinkVoucherResponse></SOAP-ENV:Body></SOAP-ENV:Envelope>

So, how to comply with our (future) customer IBM soap firewall ?

Which part of the raw file is about the DTD ?

context: trying to build a startup after winning sponsored hackathon. I'm the less than tech-savy pm trying to help the tech guys.

Thank you for your time