Hyperlinks in applications don't work anymore after upgrading to version 6 when using the HTML Client

[zvooveDev]

Describe the bug After upgrading Xpra from version 4.4.6-r29-1 to 6.0-r0-1 hyperlinks in our application don't work anymore when using the HTML Client.

To Reproduce Steps to reproduce the behavior:

1. Upgrade to Xpra version 6.0-r0-1
2. Click on a link inside an application
3. The link doesn't open inside a new tab anymore. The following error is displayed in the log: New socket connection received on '/run/user/1000/xpra/635951d33320-0' Warning: remote end does not accept URLs 1 packets received (2.6K bytes) 1 packets sent (57 bytes)

System Information (please complete the following information):

• Server OS: ubuntu:22.04
• Client OS: Windows 11
• Browser: Chrome 124.0.6347.93
• Xpra Server Version 6.0-r0-1
• Xpra Client Version 12
• Application: Delphi Application running in Wine version 8.0.2

Additional context

• I can reproduce the error in 6.0-r0-1 and 5.0.8-r0-1
• Rolling back to Version 4.4.6-r29-1 (HTML Client Version 8.1) solves the issue

[totaam]

Sorry about that. Fixed by the commit ~above~ below.

Tested using xdg-open http://google.com/ from within a basic session.