Revision 528738

net-im/telegram-desktop: Update to 1.9.21

Latest ChangeLog:
https://github.com/telegramdesktop/tdesktop/releases/tag/v1.9.21

Accummulated changes from 1.9.14:

* Bug fixes and other minor improvements.
* Fix a possible crash in animated stickers rendering.
* Fix blurred thumbnails in albums with video files.
* Fix crash in shared links search.
* Improved spellchecking on Windows 7 and Linux.
* Mark new messages as read while scrolling down through them.
* Spell checker on Windows 7.

PR:	244900
Submitted by:	henry.hu.sh@gmail.com (maintainer)