pjproject_bundled: Disable G.729 from Belledonne Communications.

When <http://github.com/BelledonneCommunications/bcg729> is installed, PJProject
tries to link that. Support for this bcg729 was added with PJProject 2.7. The
issue happens, because Teluu enabled that new feature on default.

ASTERISK-27584
Reported by: Stuart Henderson

Change-Id: I88b6b18ad777bcfe2d8201187b4b90eec0a172a6