[Nut-upsuser] Adding a 'refresh' value to the upsstats web page

[Jim Neeland]

I'd like to have the UPS status web page automatically refreshed.
I've found a reference to using @REFRESH@ in the upsstats.html
page, but as far as I can tell in looking at the code, somewhere I
need to provide a value to the refreshdelay variable, and I see no
way to do that other than changing the source code.  I'm using
nut 2.2.