[REG 5.12.4 -> 5.13.0] QTableView::sortByColumn() no longer allows re-sorting if sortingEnabled

Since commit d0f909f, QTableView::sortByColumn() no longer calls sort() on the model if sortingEnabled is true, relying on setSortIndicator() to do the job.  This has no effect if the column+order requested matches the current sort indicator, meaning that re-sorting after inserting/modifying model items no longer works.  This apparently also breaks calling sortByColumn() for the first time after populating the model if sortingEnabled has already been set beforehand, which will be the case when using uic.