Process sequential messages received in CONFIRMED_NA state

Due to UDP race conditions, sequential messages may be received
before the ACK confirming the initial INVITE ( eg. Re-INVITE sent
immediately as the call is established in order to force
a specific codec ) - also push these requests through the whole
dialog processing in order to avoid any future issues ( eg. CSEQ
updating which, if left unprocessed, will lead to generating out
of order sequentials by OpenSIPS )

modules/dialog/dlg_handlers.c

@@ -1595,7 +1595,7 @@ void dlg_onroute(struct sip_msg* req, str *route_params, void *param)
 	}
 
 	if ( (event==DLG_EVENT_REQ || event==DLG_EVENT_REQACK)
-	&& new_state==DLG_STATE_CONFIRMED) {
+	&& (new_state==DLG_STATE_CONFIRMED || new_state==DLG_STATE_CONFIRMED_NA) ) {
 		LM_DBG("sequential request successfully processed (dst_leg=%d)\n",
 			dst_leg);