ComboBox: Fix warning when model not ready

Task-number: QTBUG-31135

Change-Id: I0d9b0a3cf9d1036e6940e10944c711cdd23d858a
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>
Reviewed-by: Caroline Chao <caroline.chao@digia.com>

src/controls/ComboBox.qml

@@ -146,7 +146,7 @@ Control {
 
         Instantiator {
             id: popupItems
-            active: popup.ready
+            active: false
             MenuItem {
                 text: popup.textRole === '' ?
                         modelData :
@@ -157,11 +157,14 @@ Control {
             }
             onObjectAdded: popup.insertItem(index, object)
             onObjectRemoved: popup.removeItem(object)
+
         }
 
         function resolveTextValue(initialTextRole) {
-            if (!ready || !model)
+            if (!ready || !model) {
+                popupItems.active = false
                 return;
+            }
 
             var get = model['get'];
             if (!get && popup.__modelIsArray) {
@@ -192,6 +195,7 @@ Control {
                     textRole = roleName
                 }
             }
+            popupItems.active = true
         }
 
         function show() {