Update file selection whenever an item is selected, not just clicked.

* This catches when you use typing to find an item, or select with the
  arrow keys.

qrenderdoc/Windows/Dialogs/VirtualFileDialog.h

@@ -61,6 +61,9 @@ private slots:
   void on_forward_clicked();
   void on_upFolder_clicked();
 
+  // manual slots
+  void fileList_selectionChanged(const QItemSelection &selected, const QItemSelection &deselected);
+
 private:
   Ui::VirtualFileDialog *ui;