account: Make stack non-homogeneous

The spinner should be at the center of the view, not the other child of
the stack.
4 jobs for master in 24 minutes and 51 seconds (queued for 1 second)
Status Job ID Name Coverage
  Check
passed #245919
check

00:00:20

 
  Test
passed #245920
flatpak

00:16:43

 
  Deploy
passed #245921
pages

00:07:47

passed pages:deploy

00:00:02