Dear Maintainer,

Calls and videoconference are broken due to old libsrtp (2.2) shipped on libtgowt-0~git20230105.5098730+dfsg-2 (stable)
as a third_party sourcem module.

Starting on libtgowt-0~git20230615.a45d8b8+dfsg-2 (testing), libsrtp (2.5) is shipped as a third_party module.
Upstream changes are:
- CMake: Fix build with libsrtp v2.5.0. - https://github.com/desktop-app/tg_owt/commit/9d120195334db4f232c925529aa7601656dc59d7
- Build: Add explicit libsrtp_config. - https://github.com/desktop-app/tg_owt/commit/0614aac699b1a53242ffe2664e3724533bf64f97
- Build: Use libsrtp as a submodule. - https://github.com/desktop-app/tg_owt/commit/6894e86eef8809d42b66eb85e376006f2a816a56

This update fixes the issue, but requires telegram-desktop to be rebuild against libtgowt from testing
or another option could be to use the system libsrtp2 library already at v2.5 on stable, instead of the third_party one.

Oh!, my bad I made the mistake of not looking at the source for

libtgowt-0~git20230615.a45d8b8+dfsg-2

The points I was suggesting are already part of the that libtgowt release.

It is now using the system libsrtp2 library and that fixes the
voice/video calls, I suppose it's only needed to port

libtgowt-0~git20230615.a45d8b8+dfsg-2

to stable and get telegram-desktop rebuild, you may close this at will.

Thank you for all your work. o/