"Error while downloading ... to ..." caused by a malformed Accept HTTP header

Requests to an Apache HTTP server results in code 500 because of this OpenJDK bug (specifically caused by the *; q=.2 part). This prevents the extension to automatically download http://files.mcupdater.com/ServerPackv2.xsd. The complete error message is Error while downloading 'http://files.mcupdater.com/ServerPackv2.xsd' to '/home/user/.lemminx/cache/http/files.mcupdater.com/ServerPackv2.xsd' : '[java.io.IOException] Server returned HTTP response code: 500 for URL: http://files.mcupdater.com/ServerPackv2.xsd with code: 500 Internal Server Error'..

VSCode info:

Version: 1.81.1
Commit: 6c3e3dba23e8fadc360aed75ce363ba185c49794
Date: 2023-08-09T22:18:39.991Z
Electron: 22.3.18
ElectronBuildId: 22689846
Chromium: 108.0.5359.215
Node.js: 16.17.1
V8: 10.8.168.25-electron.0
OS: Linux x64 5.15.0-86-generic

Extension info:

Name: XML
Id: redhat.vscode-xml
Description: XML Language Support by Red Hat
Version: 0.26.1
Publisher: Red Hat
VS Marketplace Link: https://marketplace.visualstudio.com/items?itemName=redhat.vscode-xml

PS: I'm clueless about how VSCode extensions are packaged, so this might not be the right place to post this issue. Maybe this is a user-side issue that lies in the OpenJDK installed on the system. But it seems that the server/lemminx-linux binary embed the JVM.

Start by reproducing the failed download of http://files.mcupdater.com/ServerPackv2.xsd and inspect how the packaged server/lemminx-linux binary constructs its HTTP request. Check the embedded JVM and Accept header behavior against the linked OpenJDK bug. Done means the Apache request no longer returns HTTP 500 and the XSD downloads successfully.