Fixed? Re: video meeting technical issues

I think at least my problem (participant list+chat but no video/audio, 
and frequent disconnects) was at my end, not the server's, and is now 
fixed.  I don't know whether the other people with issues had the same 
issue.

I think the cause was that I had AppArmor blocking it (with my own 
profile, but I think the profile in apparmor-profiles also has this bug) 
- if you're using that, allow all of these.  This became an issue in 
bookworm, because earlier versions of Debian apparmor didn't actually 
enforce network rules.

   network inet stream,
   network inet6 stream,
   network inet dgram,
   network inet6 dgram,
   network netlink raw,

Other security tools might have similar issues.  This probably affects 
all in-browser video calls, not just Jitsi.

Testing: this issue is easy to miss because it isn't visible when 
there's only 1 in the call (the your-own-video window still works). 
Jitsi doesn't work between tabs/windows of the same Firefox instance, 
but it *does* work between two Firefox instances using different 
profiles (-P option of firefox-esr) on the same computer.