APMFirmwarePlugin: Add new errorOccurred for Qt 5.15 builds

Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>

src/FirmwarePlugin/APM/APMFirmwarePlugin.cc

@@ -793,7 +793,11 @@ void APMFirmwarePlugin::_soloVideoHandshake(Vehicle* vehicle, bool originalSoloF
 
     socket->connectToHost(_artooIP, _artooVideoHandshakePort);
     if (originalSoloFirmware) {
+#if QT_VERSION < QT_VERSION_CHECK(5, 15, 0)
         QObject::connect(socket, static_cast<void (QTcpSocket::*)(QAbstractSocket::SocketError)>(&QTcpSocket::error), this, &APMFirmwarePlugin::_artooSocketError);
+#else
+        QObject::connect(socket, &QAbstractSocket::errorOccurred, this, &APMFirmwarePlugin::_artooSocketError);
+#endif
     }
 }