freeradius3: A couple of small fixes

freeradius3: A couple of small fixes

- Moves /etc/freeradius3/sites-{enabled,available}/inner-tunnel to be part of
  the freeradius3-mod-eap package. This prevents conflicts between
  freeradius3-mod-eap-peap and freeradius3-mod-eap-ttls which both included the
  file before. This fixes LEDE bug FS#678.

- Change the demo cert validity to be 1 year instead of 60 days. Should keep the
  cert valid for the duration of the LEDE release cycle (with some slack). This
  fixes #4239.

Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>