spice-widget: fix widget size request on HiDPI when scaling is disabled

Signed-off-by: Haochen Tong <i@hexchain.org>
2 jobs for fix-spice-hidpi in 3 minutes and 44 seconds (queued for 23 seconds)
latest
Status Job ID Name Coverage
  Test
passed #3544938
fedora

00:03:44

passed #3544939
windows

00:01:26