disable Bugzilla collectstats.pl

background: bug 29203

2 more cronjobs that used to work on kaulen
and are existing for historic reasons and we puppetized
but collectstats.pl is actually missing now?

disabling until that is either added or removed completely,
because this too created a lot of cron spam from both
prod and labs test instance

/bin/sh: 1: /srv/org/wikimedia/bugzilla/collectstats.pl: not found

so if we want it and it's still appropriate for 4.4 we need to add it

Change-Id: Ia76b4093d856f15a51218277f68e9b4540c4e2e6
Merge "disable Bugzilla collectstats.pl" into production