wsus_client should support the AlwaysAutoRebootAtScheduledTimeMinutes key

Hi,

as a continuation of MODULES-3016, I would kindly ask to add support for another Windows register key: AlwaysAutoRebootAtScheduledTimeMinutes.

As described in MODULES-3016 AlwaysAutoRebootAtScheduledTime forces the reboot of the machine after update, even when there are some users logged on. The reboot is forced not sooner than 24h after the instalation.
Forced restart can be launched just after the instalation using the AlwaysAutoRebootAtScheduledTimeMinutes key. The valid range is between 15 and 180 minutes.

Set of these two keys basically can replace the behaviour of whole group policy: "Always automatically restart at the scheduled time"

Thanks!