mailman - monitor archive page (of wikimedia-l)

also monitor the archive page, follow-up to
Ifd3904984bf3417f0 where we check the listinfo page

the difference is this checks HTTP, not HTTPS
but also for actual content "The Wikimedia-l Archives"
on http://lists.wikimedia.org/pipermail/wikimedia-l/

this needs to be adjusted if I3511f4b0d0185d1e gets merged

Change-Id: I77c2f56eedd86271ab7564e1b6d5a2c4df7c02b8
RT: 7878
Merge "mailman - monitor archive page (of wikimedia-l)" into production