Telegram-FOSS: Add version 1.4.9b and make it current

Merged username-removed-25180 requested to merge (removed):master into master

Version 1.4.9b of Telegram-FOSS includes some improvements for compensating the lack of GCM, improving the arrival time for notifications.

I wasn't sure about what value should be set for "Version Code", so I just wrote a correlative value from previous build. Probably this is wrong.