Reduce number of stats items for stanchion
Reduce number of stats items for stanchion

Because unused items has been removed.
cf https://github.com/basho/stanchion/pull/102/files

GabrielNicolasAvellaneda/riak_cs,basho/riak_cs,dragonfax/riak_cs,GabrielNicolasAvellaneda/riak_cs,dragonfax/riak_cs,basho/riak_cs,GabrielNicolasAvellaneda/riak_cs,basho/riak_cs,dragonfax/riak_cs,basho/riak_cs,GabrielNicolasAvellaneda/riak_cs,dragonfax/riak_cs