utils/stats: remove dead code
utils/stats: remove dead code

prometheus/prometheus,AlekSi/prometheus,alileza/prometheus,yanghongkjxy/prometheus,Gouthamve/prometheus,Conorbro/prometheus,keegancsmith/prometheus,GoogleCloudPlatform/prometheus,brancz/prometheus,keegancsmith/prometheus,kangwoo/prometheus,brancz/prometheus,AlekSi/prometheus,amorken/prometheus,Gouthamve/prometheus,yanghongkjxy/prometheus,Conorbro/prometheus,Conorbro/prometheus,AlekSi/prometheus,Stackdriver/stackdriver-prometheus,alileza/prometheus,kangwoo/prometheus,alileza/prometheus,Stackdriver/stackdriver-prometheus,alileza/prometheus,Gouthamve/prometheus,prometheus/prometheus,GoogleCloudPlatform/prometheus,yanghongkjxy/prometheus,Gouthamve/prometheus,GoogleCloudPlatform/prometheus,yanghongkjxy/prometheus,prometheus/prometheus,Stackdriver/stackdriver-prometheus,prometheus/prometheus,kangwoo/prometheus,alileza/prometheus,brancz/prometheus,amorken/prometheus,keegancsmith/prometheus,AlekSi/prometheus,prometheus/prometheus,brancz/prometheus,GoogleCloudPlatform/prometheus,amorken/prometheus,kangwoo/prometheus,GoogleCloudPlatform/prometheus,amorken/prometheus,Conorbro/prometheus,Stackdriver/stackdriver-prometheus,keegancsmith/prometheus,keegancsmith/prometheus