WATCHDOG: Restart providers with SIGUSR2 after time drift
    
    Restarting the providers using the already implemented SIGUSR2 (for
    method .resetOffline, used after netlink detects an interface change)
    when a time drift is detected, ensures that affected connection retries
    (e.g. LDAP) will be rescheduled immediately instead of having to wait
    the time shifted to return to its normal execution.
    
    Resolves:
    https://pagure.io/SSSD/sssd/issue/3285
    
    Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>
    Reviewed-by: Fabiano Fidêncio <fidencio@redhat.com>