[rancid] nxrancid small suggestion/patch

[Deny IP Any Any]

In my environment, adding

{'show environment fex all fan' => 'ShowEnv'},

to my nxrancid's @commandtable yields valuable information about the
power supply health of my N2K FEXs; it may be a valuable addition to
others as well.

I can provide this trivial change in DIFF format if that would be preferred.

[john heasley]

Post by Deny IP Any Any
In my environment, adding
{'show environment fex all fan' => 'ShowEnv'},
power supply health of my N2K FEXs; it may be a valuable addition to
others as well.

on which platform(s) and does this create any "cycling" output, such as
fan speeds?