QmlJSEditor: remove modeUpdated method

It does not say what it does, it is better for understanding
to call the direct method instead.

Change-Id: I2150d4c84254f684474e353995b466b59d4844c0
Reviewed-by: Marco Benelli <marco.benelli@qt.io>

src/plugins/qmljseditor/qmljsoutline.h

@@ -76,7 +76,6 @@ public:
     virtual QVariantMap settings() const override;
 
 private:
-    void modelUpdated();
     void updateSelectionInTree(const QModelIndex &index);
     void updateSelectionInText(const QItemSelection &selection);
     void updateTextCursor(const QModelIndex &index);