modules/ims_charging: fixed failed reservation bug

	- Reservation checks dialog integrity with h_entry < 0
	- The hash that creates h_entry can return 0 - this check should be <= 0

modules/ims_charging/ro_timer.c

@@ -402,7 +402,7 @@ void ro_session_ontimeout(struct ro_tl *tl) {
 		update_stat(billed_secs, used_secs);
 
 		if (ro_session->callid.s != NULL
-				&& ro_session->dlg_h_entry	> 0
+				&& ro_session->dlg_h_entry	>= 0
 				&& ro_session->dlg_h_id > 0
 				&& ro_session->ro_session_id.s != NULL)
 		{