b2b_logic: ignore replies to NOTIFYs sent while bridging

This will get rid of the races between the processing of the replies for the
NOTIFY and the subsequent BYE sent to the bridge initiator. The entity
might be already deleted as a result of handling the 200 OK for the BYE
before we try to do a lookup again for handling the NOTIFY reply. These
races would not produce any significant negative effects but OpenSIPS
would log unnecessary 'No b2b_key match found' errors.

(cherry picked from commit a72cfbe)

modules/b2b_logic/logic.c

@@ -626,6 +626,7 @@ int process_bridge_notify(b2bl_entity_id_t *entity, unsigned int hash_index, str
 	memset(&req_data, 0, sizeof(b2b_req_data_t));
 	PREP_REQ_DATA(entity);
 	req_data.method = &method_notify;
+	req_data.no_cb = 1;
 	req_data.client_headers = &entity->hdrs;
 	req_data.body = 0;
 	if (!msg) {
@@ -1490,10 +1491,6 @@ int _b2b_handle_reply(struct sip_msg *msg, b2bl_tuple_t *tuple,
 			statuscode);
 
 		/* if the scenario state is B2B_BRIDGING_STATE -> we should have a reply for INVITE */
-		/* extract the method from Cseq header */
-
-		if(method_value == METHOD_NOTIFY) goto done1; /* Silently ignore reply on NOTIFY */
-
 		if(method_value != METHOD_INVITE)
 		{
 			LM_ERR("Wrong scenario state [B2B_BRIDGING_STATE] for this"