GridLayout did not evaluate Layout.{row,column} changes on its items

Only the initial Layout.row and Layout.column values were
respected - any further changes were ignored.

Task-number: QTBUG-32767

Change-Id: I018800665e64158e8b38762fc29a5d3025776ff0
Reviewed-by: J-P Nurmi <jpnurmi@digia.com>