b2b_logic: set late SDP negociation flag

For the entity that initiates a call, late SDP negociation is used, because
the SDP of the first entity is not known. This patch sets the late_sdp flag
for that entity, to flag the b2b logic to send the ACK with SDP.

This bug was reported on the mailing list by Sebastian Sastre.

(cherry picked from commit 20df836)

modules/b2b_logic/logic.c

@@ -2533,6 +2533,7 @@ int process_bridge_action(struct sip_msg* msg, b2bl_entity_id_t* curr_entity,
 		entity->stats.call_time = get_ticks();
 		entity->type = B2B_CLIENT;
 		entity->peer = bridge_entities[1];
+		entity->late_sdp = 1;
 		shm_free(bridge_entities[0]);
 
 		tuple->bridge_entities[0] = entity;