netdisco-mibs pr239

[inphobia]

not sure if adding that dummy root module is a good idea, but it makes reports/all prettier.

if that's not wanted just roll back 1 commit to: https://github.com/netdisco/netdisco-mibs/commit/f2d55d4b69b632b093d5fcc160c01a6cc402b992

quick link to diff with or without dummy mib: https://github.com/inphobia/netdisco-mibs/compare/f2d55d4...f94ab80