thermostat: show force off in zones when holiday mode is on

soft/thermostat/src/zoneitem.cpp

@@ -80,6 +80,10 @@ void ZoneItem::refresh(void)
 		break;
 	}
 
+	if (s->m_end_holiday > QDateTime::currentDateTime()) {
+		m_target_temperature = FORCE_OFF;
+	}
+
 	/* Zone name */
 	text += QString("<center><b>") + m_name + QString("</b></center>");