Fix bug that was clearing MAINT mode on nodes scheduled for reboot (bug
    introduced in version 16.05.5 to address bug in overlapping reservations,
    commit 5eee1d28). Note that a node's
    MAINT flag is used for both a requested reboot and maintenance reservation.
    What I'd like to do is add a new node state flag to differenciate
    between these two cases, but that involves some significant changes
    that could introduce instability, so it will be defered to version
    17.02
bug 3210