Upgrade libXext to 1.3.3

[bellini666]

Please upgrade libXext to 1.3.3 as a fix to this: ValveSoftware/steam-for-linux#3364

[scottlu]

Thanks for the report, we're working on a fix.

[berdario]

Any update on the fix? I got a 19GB log file, full of 272371094 lines all with the same message.

This subsequently leaded to data loss, since it exhausted all free disk space, and when exiting the game I was playing it was unable to save to disk properly

[scottlu]

The fix for this is in the steam public beta that was released today.