Remove node label
Remove node label

Since the exporter returns stats for the local node only, it's not
necessary to set this as a label since prometheus will include the
instance label to identify the node. If a custom node name is
necessary, this can be specified in the prometheus target
configuration:

http://prometheus.io/docs/operating/configuration/#target-groups-target_group

rayhou/elasticsearch_exporter,jrummler/elasticsearch_exporter,mattkanwisher/elasticsearch_exporter,yackushevas/elasticsearch_exporter,justwatchcom/elasticsearch_exporter,ewr/elasticsearch_exporter,William-Yeh/es_cluster_exporter,Kuckkuck/elasticsearch_exporter