Load 8021q module to recognize vlan-tagged traffic on networks with vlans

[william-stearns]

While Zeek will process vlan-tagged traffic, that traffic has to make it from the interface up to Zeek during the raw packet capture. This won't happen unless the 8021q module is loaded.
Requests:

1. load the 8021q module by hand during initial install:
   sudo modprobe 8021q || true
2. add the line "8021q" to /etc/modules so it's automatically loaded after following boots
   echo -e '\n8021q' | sudo tee -a /etc/modules >/dev/null
   The above change should have no effect on networks that do not use vlans.
   Should this be built into the kernel (as opposed to being a loadable module), step 1 may come back with a failure so we need to add "|| true" to the modprobe command line. (No change is needed for (2) )

[william-stearns]

Addressed by https://github.com/activecm/AC-Hunter/pull/2197