WebRTC: meet.jit.si videocall does not work

krillin, rc-proposed/bq-aquaris.en channel, revision 456

I previously reported bug #1466015 about meet.jit.si not working on webbrowser-app, but that bug was marked as duplicate of another bug that is now marked as "Fix Released".
But meet.jit.si still does not work.
I'm opening a new bug since the errors in the log are different from the ones I reported in the previous bug.

How to reproduce:
1) visit meet.jit.si
2) click on Go to start a new videocall

Expected outcome:
a videocall is started

Actual outcome:
nothing happens

Additional info
Here's the content of webbrowser-app.log when visiting meet.jit.si:
qml: [JS] (https://meet.jit.si/:8) (TIME) index.html loaded:
qml: [JS] (https://d3f5ootf0jzs2j.cloudfront.net/1380/libs/lib-jitsi-meet.min.js?v=1380:1) Uncaught TypeError: Cannot read property '1' of null
qml: [JS] (https://d3f5ootf0jzs2j.cloudfront.net/1380/libs/app.bundle.min.js?v=1380:25) DEPRECATED JS - Cookie has been deprecated since 5.8.0 and will be removed in a future release. Use cookie instead.
qml: [JS] (https://d3f5ootf0jzs2j.cloudfront.net/1380/libs/app.bundle.min.js?v=1380:15) Uncaught ReferenceError: JitsiMeetJS is not defined
qml: [JS] (:0) SVG's SMIL animations (<animate>, <set>, etc.) are deprecated and will be removed. Please use CSS animations or Web animations instead.
[1023/145548:WARNING:webmediaplayer_impl.cc(346)] Using MultibufferDataSource
[1023/145548:WARNING:webmediaplayer_impl.cc(346)] Using MultibufferDataSource
[1023/145548:WARNING:webmediaplayer_impl.cc(346)] Using MultibufferDataSource
shm_open() failed: Permission denied
shm_open() failed: Permission denied