switch bugzilla.wikipedia.org to wikimedia-lb

wikimedia-lb, not wikipedia-lb, per Ariel's
discussion with Mark etc., it's more generic

this should fix RT #2675 (at least partly)

the redirect for this already existed in cluster
Apache config all this time:

redirects.conf:        bugzilla.wikipedia.org
RewriteCond %{HTTP_HOST} =bugzilla.wikipedia.org [OR]..
RewriteRule ^(.*)$ https://bugzilla.wikimedia.org$1 [R=302,L,NE]

Change-Id: I303339f00178eeca4c95a6baaca74bb9a6c8cf71