fix(userdata template): put `nse` function in FHS

Gentoo's `/etc/profile` automatically sources all `.sh` files in
`/etc/profile.d` when bash is run. This reduces boot time at the expense
of an extra file read per shell opened. However this is a minimal cost
for the FHS convenience. Trivial fix.
Merge pull request #1444 from deis/fix/userdata/make-nse-profile.d-function-script

fix(userdata template): put `nse` function in FHS