Update header.html
Update header.html

Changed three meta tag links pointing to company logo as logo.png to influx-logo-complete-dark.svg.
influxdata/docs.influxdata.com,influxdb/docs.influxdata.com,influxdb/docs.influxdata.com,influxdata/docs.influxdata.com,influxdata/docs.influxdata.com,influxdb/docs.influxdata.com,influxdata/docs.influxdata.com,influxdata/docs.influxdata.com