Fixed typo in kafka event handler page.
Fixed typo in kafka event handler page.

influxdata/docs.influxdata.com,influxdb/docs.influxdata.com,influxdata/docs.influxdata.com,influxdb/docs.influxdata.com,influxdata/docs.influxdata.com,influxdb/docs.influxdata.com,influxdata/docs.influxdata.com,influxdata/docs.influxdata.com