RenameFileDialog: a widget can't have two layouts
This silences a warning: QLayout: Attempting to add QLayout "" to QWidget "", which already has a layout
"page" widget already has a child/main layout, because topLayout was constructed with "page" as its parent. And "horizontalLayout" will be reparented by the addLayout() call a couple of lines down, so it's OK.
GIT_SILENT