[ImgBot] Optimize images

*Total -- 20,074.27kb -> 15,649.34kb (22.04%)

/btrfs/images/btrfs_metric.png -- 16.23kb -> 7.50kb (53.81%)
/snowflake/images/custom_query.png -- 487.13kb -> 260.79kb (46.46%)
/etcd/images/etcd_dashboard.png -- 167.71kb -> 93.95kb (43.98%)
/redisdb/images/redis-dash.png -- 271.88kb -> 162.57kb (40.2%)
/snmp/images/bandwidth-usage-formula-small.png -- 14.89kb -> 9.07kb (39.09%)
/haproxy/images/haproxy-dash.png -- 353.72kb -> 222.47kb (37.11%)
/druid/images/druid_dashboard_overview.png -- 186.81kb -> 120.16kb (35.68%)
/vsphere/images/vsphere_graph.png -- 625.84kb -> 410.42kb (34.42%)
/mysql/images/mysql-dash-dd.png -- 278.58kb -> 183.40kb (34.17%)
/postgres/images/postgresql_dashboard.png -- 733.81kb -> 487.19kb (33.61%)
/varnish/images/varnish.png -- 319.27kb -> 212.87kb (33.33%)
/hive/assets/dashboards/overview.png -- 362.80kb -> 244.54kb (32.6%)
/ambari/assets/images/base_dashboard.png -- 370.04kb -> 249.64kb (32.54%)
/mesos_slave/images/mesos_dashboard.png -- 241.78kb -> 164.88kb (31.81%)
/mesos_master/images/mesos_dashboard.png -- 241.78kb -> 164.88kb (31.81%)
/harbor/assets/dashboards/overview.png -- 146.79kb -> 100.60kb (31.47%)
/docs/developer/assets/images/snmp-architecture.png -- 57.94kb -> 40.51kb (30.09%)
/supervisord/images/supervisorevent.png -- 38.84kb -> 27.49kb (29.21%)
/docs/developer/assets/images/snmp-architecture-cluster-agent.png -- 78.08kb -> 55.93kb (28.37%)
/ibm_db2/images/dashboard_overview.png -- 347.01kb -> 254.66kb (26.61%)
/openldap/images/snapshot.png -- 47.57kb -> 36.07kb (24.17%)
/spark/images/spark_dashboard.png -- 657.96kb -> 501.59kb (23.77%)
/fluentd/images/snapshot-fluentd.png -- 63.55kb -> 48.45kb (23.76%)
/cassandra_nodetool/images/cassandra_dashboard.png -- 633.12kb -> 484.04kb (23.55%)
/cassandra/images/cassandra_dashboard.png -- 633.12kb -> 484.04kb (23.55%)
/tomcat/images/tomcat_dashboard.png -- 142.84kb -> 109.42kb (23.4%)
/spark/images/sparkgraph.png -- 151.80kb -> 117.20kb (22.79%)
/couchbase/images/couchbase_graph.png -- 53.11kb -> 41.17kb (22.48%)
/zk/images/zk_dashboard.png -- 539.36kb -> 419.25kb (22.27%)
/apache/images/apache_dashboard.png -- 448.43kb -> 348.71kb (22.24%)
/consul/images/consul-dash.png -- 127.63kb -> 101.22kb (20.69%)
/nginx/images/nginx-board-5.png -- 161.15kb -> 129.44kb (19.68%)
/oracle/images/oracle_dashboard.png -- 540.54kb -> 434.88kb (19.55%)
/openstack/images/openstack_dashboard.png -- 795.19kb -> 640.23kb (19.49%)
/nginx/images/nginx_dashboard.png -- 1,164.52kb -> 962.47kb (17.35%)
/hdfs_namenode/images/hadoop_dashboard.png -- 498.80kb -> 416.83kb (16.43%)
/hdfs_datanode/images/hadoop_dashboard.png -- 498.80kb -> 416.83kb (16.43%)
/mapreduce/images/mapreduce_dashboard.png -- 498.80kb -> 416.83kb (16.43%)
/yarn/images/yarn_dashboard.png -- 498.80kb -> 416.83kb (16.43%)
/ceph/images/ceph_dashboard.png -- 684.60kb -> 573.26kb (16.26%)
/kafka_consumer/images/kafka_dashboard.png -- 753.04kb -> 630.66kb (16.25%)
/kafka/images/kafka_dashboard.png -- 753.04kb -> 630.66kb (16.25%)
/elastic/images/elasticsearch-dash.png -- 212.66kb -> 178.82kb (15.91%)
/kubernetes/images/kubernetes_dashboard.png -- 965.58kb -> 812.18kb (15.89%)
/gunicorn/images/gunicorn-dash.png -- 144.30kb -> 124.54kb (13.69%)
/rabbitmq/images/rabbitmq_dashboard.png -- 502.60kb -> 434.81kb (13.49%)
/couch/images/couchdb_dashboard.png -- 550.50kb -> 477.69kb (13.23%)
/mongo/images/mongo_dashboard.png -- 861.85kb -> 750.56kb (12.91%)
/amazon_eks/images/amazon_eks_dashboard.png -- 461.55kb -> 408.33kb (11.53%)
/sqlserver/images/sqlserver_dashboard.png -- 514.74kb -> 458.10kb (11%)
/go_expvar/images/go_graph.png -- 25.84kb -> 24.48kb (5.26%)
/docs/developer/assets/images/logo.svg -- 3.84kb -> 3.66kb (4.63%)
/solr/images/solrgraph.png -- 22.14kb -> 21.22kb (4.14%)
/riakcs/images/riakcs_dashboard.png -- 119.42kb -> 118.73kb (0.58%)
/twistlock/images/twistlock.svg -- 2.58kb -> 2.58kb (0.04%)

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