Fix add machine dialog state

resources/qml/Cura.qml

@@ -814,7 +814,12 @@ UM.MainWindow
     Connections
     {
         target: Cura.Actions.addMachine
-        onTriggered: addMachineDialog.show()
+        onTriggered:
+        {
+            // Make sure to show from the first page when the dialog shows up.
+            addMachineDialog.resetModelState()
+            addMachineDialog.show()
+        }
     }
 
     AboutDialog

resources/qml/WelcomePages/WizardDialog.qml

@@ -30,12 +30,9 @@ Window
     property var model: null  // Needs to be set by whoever is using this dialog.
     property alias progressBarVisible: wizardPanel.progressBarVisible
 
-    onVisibilityChanged:
+    function resetModelState()
     {
-        if (visible)
-        {
-            model.resetState()
-        }
+        model.resetState()
     }
 
     WizardPanel