This is done even if the emf contains a previous EMR_SETSTRETCHBLTMODE
record.

Thanks to Sebastián Aedo for some of the testing.
Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Esme Povirk <esme@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>