Remove spetrea from icinga's analytics contact group

spetrea is no longer part of the Analytics team. Removal requested by
tnegrin in

  https://lists.wikimedia.org/mailman/private/ops/2014-June/035156.html

Change-Id: Idfa4c25b583031cb49e9ba309dda99fea5175543
Merge "Remove spetrea from icinga's analytics contact group" into production