Relax the dialog state machine - allow PRACK after dialog is established

There are some weird UDP scenarios where the PRACK may land on the server after the ACK. Rejecting the PRACK at dialog level leads to infinit looping (if used with TH). Better be more flexible and ignore PRACKs after ACK.

modules/dialog/dlg_hash.c

@@ -1004,6 +1004,7 @@ void next_state_dlg(struct dlg_cell *dlg, int event, int dir, int *old_state,
 			switch (dlg->state) {
 				case DLG_STATE_EARLY:
 				case DLG_STATE_CONFIRMED_NA:
+				case DLG_STATE_CONFIRMED:
 					break;
 				default:
 					log_next_state_dlg(event, dlg);