Clean up multicast examples

They're small, not much to polish.

Pick-to: 6.5
Change-Id: Iada573504de557ab18381370bb9760b1f60cc2e4
Reviewed-by: Konrad Kujawa <konrad.kujawa@qt.io>
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>

examples/network/doc/src/multicastreceiver.qdoc

@@ -3,10 +3,12 @@
 
 /*!
     \example multicastreceiver
-    \title Multicast Receiver Example
+    \title Multicast Receiver
+    \meta category {Networking}
+    \meta tags {network,multicast,ipv6,ipv4,udp}
     \ingroup examples-network
     \brief Demonstrates how to receive information sent to a multicast group.
 
-    This example demonstrates how to receive messages sent to a multicast group
-    \image multicastreceiver-example.png
+    This example demonstrates how to receive messages sent to a multicast group.
+    \image multicastreceiver-example.webp
 */

examples/network/doc/src/multicastsender.qdoc

@@ -3,12 +3,14 @@
 
 /*!
     \example multicastsender
-    \title Multicast Sender Example
+    \title Multicast Sender
+    \meta category {Networking}
+    \meta tags {network,multicast,ipv6,ipv4,udp}
     \ingroup examples-network
     \brief Demonstrates how to send messages to a multicast group.
 
     This example demonstrates how to send messages to the clients of a
     multicast group.
 
-    \image multicastsender-example.png
+    \image multicastsender-example.webp
 */

examples/network/multicastreceiver/receiver.cpp

@@ -47,7 +47,7 @@ void Receiver::processPendingDatagrams()
 
     // using QUdpSocket::readDatagram (API since Qt 4)
     while (udpSocket4.hasPendingDatagrams()) {
-        datagram.resize(int(udpSocket4.pendingDatagramSize()));
+        datagram.resize(qsizetype(udpSocket4.pendingDatagramSize()));
         udpSocket4.readDatagram(datagram.data(), datagram.size());
         statusLabel->setText(tr("Received IPv4 datagram: \"%1\"")
                              .arg(datagram.constData()));