Debugger: Remove one use of TreeItem::setFlags

One step towards the removal of the TreeItem::m_flags member
that's unused in most instances.

Change-Id: I0cdc3d1e8a47c3925fb54c129b724ded8721577b
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/debugger/console/consoleitemmodel.cpp

@@ -67,9 +67,6 @@ void ConsoleItemModel::shiftEditableRow()
     int position = rootItem()->childCount();
     Q_ASSERT(position > 0);
 
-    // Disable editing for old editable row
-    rootItem()->lastChild()->setFlags(Qt::ItemIsEnabled | Qt::ItemIsSelectable);
-
     appendItem(new ConsoleItem(ConsoleItem::InputType), position);
     emit selectEditableRow(index(position, 0, QModelIndex()), QItemSelectionModel::ClearAndSelect);
 }