Comment # 4 on bug 1049127 from Oliver Kurz

The cursor on the black screen is the first thing to show up when plasma is not
yet fully loaded. I assume that we simply need to bump the timeout waiting for
the desktop after this reboot, especially in an upgraded system. The test uses
`wait_boot` already. The timeout parameter can be configured with the
`ready_time` parameter. Please check history and other scenarios for related
failures and then bump timeout accordingly.