updated to use forwardMavlinkHostName visible property for visible setting of qml items

src/ui/preferences/MavlinkSettings.qml

@@ -166,14 +166,14 @@ Rectangle {
                         QGCLabel {
                             width:              _labelWidth
                             anchors.baseline:   mavlinkForwardingHostNameField.baseline
-                            visible:            QGroundControl.settingsManager.appSettings.forwardMavlink.visible
+                            visible:            QGroundControl.settingsManager.appSettings.forwardMavlinkHostName.visible
                             text:               qsTr("Host name:")
                         }
                         FactTextField {
                             id:                     mavlinkForwardingHostNameField
                             fact:                   QGroundControl.settingsManager.appSettings.forwardMavlinkHostName
                             width:                  _valueWidth
-                            visible:                QGroundControl.settingsManager.appSettings.forwardMavlink.visible
+                            visible:                QGroundControl.settingsManager.appSettings.forwardMavlinkHostName.visible
                             enabled:                QGroundControl.settingsManager.appSettings.forwardMavlink.rawValue
                             anchors.verticalCenter: parent.verticalCenter
                         }
@@ -181,7 +181,7 @@ Rectangle {
                     }
                    QGCLabel {
                         text:       qsTr("<i> Changing the host name requires restart of application. </i>")
-                        visible:    QGroundControl.settingsManager.appSettings.forwardMavlink.visible
+                        visible:    QGroundControl.settingsManager.appSettings.forwardMavlinkHostName.visible
                     }
                 }
             }