Change order of server/volume in snapshot test

This changes the order in which we create our test server and our test
volume in test_snapshot_create_delete_with_volume_in_use() to better
enable us to allow server deletion to detach the volume without hanging
on the guest.

Change-Id: Ia40ddacc5d5de3a57d19c4d60a65ba9bdc7c943d
Related-Bug: #1939108
1 file changed