Depending on our clipboard polling we can get an additional clipboard
update during the clipboard clear test.  This change forces a consistent
state when starting the test, which stops the additional window message
from possibly occurring.
Signed-off-by: Erich E. Hoover <erich.e.hoover@wine-staging.com>
Signed-off-by: Vincent Povirk <vincent@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>