Log Message:
fix a ups-nut-usb crash.  from the patch file:

  As comm_driver->get_interrupt() can return larger than the buffer size,
  limit the future accesses by this amount.  Bump the size of the buffer
  here as returns as high as 3500 have been seen.

bump ups-nut-usb revision.

with this, i am able to monitor a recent CyberPower UPS.