Don't ignore retained messages

The VRM broker will be updated to ensure that this isn't a problem
in future once more clients connect to VRM.

FlashMQ on the CerboGX doesn't emit retained messages (except for
the serial and keepalive topics) so it doesn't need special
handling there.

src/qt/ve_qitems_mqtt.cpp

@@ -379,12 +379,6 @@ void VeQItemMqttProducer::onSubscriptionMessageReceived(const QMqttMessage &mess
 		const QString keepaliveTopic = notificationPrefix + QStringLiteral("/keepalive");
 		if (topicName.compare(keepaliveTopic, Qt::CaseInsensitive) == 0) {
 			// ignore keepalive topic.
-		} else if (!mIsVrmBroker && message.retain()) {
-			// ignore retained messages, as for internet brokers (VRM)
-			// nothing will "unpublish" the topic for a device which goes offline.
-			// see issue #313 in gui-v2.
-			// for now, only enable this for non-VRM (i.e. local) brokers,
-			// as VRM is not yet using FlashMQ.
 		} else {
 			// we have a topic message which we need to expose via VeQItem.
 			const QString path = topicName.mid(notificationPrefix.size() + 1);