LibreOffice & Personas behind proxy / firewall

I am able to use Firefox and Personas at work, but loading personas from LibreOffice does not work.

I suspect this is a firewall/proxy ajustment for LibreOffice user-agent.

So what is the LibreOffice user-agent to get personas? or how to adjust the firewall/proxy to allow personas for LibreOffice?

Related: Discussion on the dev list

I sniffed my network and the User-Agent is “LibreOffice” and the protocol is DAV. Here is what I get to sustain that:

PROPFIND /persona/491813 HTTP/1.1
Connection: TE, Keep-Alive
TE: trailers
Depth: 0
Content-Length: 237
Content-Type: application/xml
Pragma: no-cache
User-Agent: LibreOffice


<?xml version="1.0" encoding="utf-8"?>
<propfind xmlns="DAV:"><prop>
<resourcetype xmlns="DAV:"/>
<IsReadOnly xmlns=""/>
<getcontenttype xmlns="DAV:"/>
<supportedlock xmlns="DAV:"/>