Prevent QML errors when model is not yet initialised

I'm not sure when this happens, but it updates this text twice: Once with 'undefined' name and once with the proper name. For the user it displays the name correctly, but it may be so fast that nothing was visible.

Discovered during work on CURA-8686.

resources/qml/WelcomePages/AddCloudPrintersView.qml

@@ -157,7 +157,7 @@ Item
                     {
                         id: cloudPrinterNameLabel
                         leftPadding: UM.Theme.getSize("default_margin").width
-                        text: model.name
+                        text: model.name ? model.name : ""
                         font: UM.Theme.getFont("large_bold")
                         color: UM.Theme.getColor("text")
                         elide: Text.ElideRight