[winswitch] [ANNOUNCE] Xpra 2.2.6: important fixes

[Antoine Martin]

Hi,

This update fixes a number of serious issues, in particular some X11
server crashes and auto-refresh loops.
Updating is strongly recommended.

Release notes:
* fix support for encryption key environment variable
* fix html-disabled option not honoured when ssl upgrades used
* fix MS Windows SSL server timeouts
* fix refresh loop with video region
* fix auto-refresh of transparent windows (was losing transparency)
* fix default printing information collection method
* fix OpenGL backend validation not honoured
* fix swapped colour channels in OpenGL client with transparent windows
  encoded as PNG
* fix webp paint errors with OpenGL disabled
* fix NVENC codec compatibility with Cython 0.28
* fix png/P encoding wrongly used in some exceedingly rare cases
* fix padding issues with very large passwords or challenge packets
* fix missing window contents when switching tabs (HTML5 client)
* fix MS Windows comtypes packaging: webcam device detection issues
* fix unmanaged X11 calls causing GTK crashes
* fix clipboard handler wrongly answering requests when disabled
* fix unlikely errors during connection cleanup
* remove outdated option from the man page, fix missing paragraphs
* disable VP9 decoding via ffmpeg on MS Windows (crashy)

Links:
https://xpra.org/trac/wiki/Source
https://xpra.org/trac/wiki/Download

Cheers
Antoine