pjsip: Add patch for resolving STUN packet lifetime issues.

In some cases it was possible for a STUN packet to be destroyed
prematurely or even destroyed partially multiple times.

This patch provided by Teluu fixes the lifetime of these
packets and ensures they aren't partially destroyed multiple
times.

https://github.com/pjsip/pjproject/pull/2709

ASTERISK-29377

Change-Id: Ie842ad24ddf345e01c69a4d333023f05f787abca