Recent channel updates have caused some issues for telega.el, mostly
because the version of tdlib (the C++ library for Telegram) and the
Emacs package are out of sync.
This overrides the version used in the Emacs package to a "known good"
commit. It would be useful to change the tdlib derivation in nixpkgs
to make this version mismatch a hard build error.
Change-Id: I9c994f783e1cc17e933432507cd13b65697efd4a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2445
Tested-by: BuildkiteCI
Reviewed-by: Profpatsch <mail@profpatsch.de>