Update changelog

(cherry picked from commit b0baffddbe9e289a0d26862f4dbfefc9091fefe2)

CHANGELOG.md

@@ -2,6 +2,45 @@
 
 # Changelog
 
+## v1.21.4 [2022-02-16]
+
+### Bugfixes
+
+- [#10491](https://github.com/influxdata/telegraf/pull/10491) `inputs.docker` Update docker memory usage calculation
+- [#10636](https://github.com/influxdata/telegraf/pull/10636) `inputs.ecs` Use current time as timestamp
+- [#10551](https://github.com/influxdata/telegraf/pull/10551) `inputs.snmp` Ensure folders do not get loaded more than once
+- [#10579](https://github.com/influxdata/telegraf/pull/10579) `inputs.win_perf_counters` Add deprecated warning and version to win_perf_counters option
+- [#10635](https://github.com/influxdata/telegraf/pull/10635) `outputs.amqp` Check for nil client before closing in amqp
+- [#10179](https://github.com/influxdata/telegraf/pull/10179) `outputs.azure_data_explorer` Lower RAM usage
+- [#10513](https://github.com/influxdata/telegraf/pull/10513) `outputs.elasticsearch` Add scheme to fix error in sniffing option
+- [#10657](https://github.com/influxdata/telegraf/pull/10657) `parsers.json_v2` Fix timestamp change during execution of json_v2 parser
+- [#10618](https://github.com/influxdata/telegraf/pull/10618) `parsers.json_v2` Fix incorrect handling of json_v2 timestamp_path
+- [#10468](https://github.com/influxdata/telegraf/pull/10468) `parsers.json_v2` Allow optional paths and handle wrong paths correctly
+- [#10547](https://github.com/influxdata/telegraf/pull/10547) `serializers.prometheusremotewrite` Use the correct timestamp unit
+- [#10647](https://github.com/influxdata/telegraf/pull/10647) Update all go.opentelemetry.io from 0.24.0 to 0.27.0
+- [#10652](https://github.com/influxdata/telegraf/pull/10652) Update github.com/signalfx/golib/v3 from 3.3.38 to 3.3.43
+- [#10653](https://github.com/influxdata/telegraf/pull/10653) Update github.com/aliyun/alibaba-cloud-sdk-go from 1.61.1004 to 1.61.1483
+- [#10503](https://github.com/influxdata/telegraf/pull/10503) Update github.com/denisenkom/go-mssqldb from 0.10.0 to 0.12.0
+- [#10626](https://github.com/influxdata/telegraf/pull/10626) Update github.com/gopcua/opcua from 0.2.3 to 0.3.1
+- [#10638](https://github.com/influxdata/telegraf/pull/10638) Update github.com/nats-io/nats-server/v2 from 2.6.5 to 2.7.2
+- [#10589](https://github.com/influxdata/telegraf/pull/10589) Update k8s.io/client-go from 0.22.2 to 0.23.3
+- [#10601](https://github.com/influxdata/telegraf/pull/10601) Update github.com/aws/aws-sdk-go-v2/service/kinesis from 1.6.0 to 1.13.0
+- [#10588](https://github.com/influxdata/telegraf/pull/10588) Update github.com/benbjohnson/clock from 1.1.0 to 1.3.0
+- [#10598](https://github.com/influxdata/telegraf/pull/10598) Update github.com/Azure/azure-kusto-go from 0.5.0 to 0.5.2
+- [#10571](https://github.com/influxdata/telegraf/pull/10571) Update github.com/vmware/govmomi from 0.27.2 to 0.27.3
+- [#10572](https://github.com/influxdata/telegraf/pull/10572) Update github.com/prometheus/client_golang from 1.11.0 to 1.12.1
+- [#10564](https://github.com/influxdata/telegraf/pull/10564) Update go.mongodb.org/mongo-driver from 1.7.3 to 1.8.3
+- [#10563](https://github.com/influxdata/telegraf/pull/10563) Update github.com/google/go-cmp from 0.5.6 to 0.5.7
+- [#10562](https://github.com/influxdata/telegraf/pull/10562) Update go.opentelemetry.io/collector/model from 0.39.0 to 0.43.2
+- [#10538](https://github.com/influxdata/telegraf/pull/10538) Update github.com/multiplay/go-ts3 from 1.0.0 to 1.0.1
+- [#10454](https://github.com/influxdata/telegraf/pull/10454) Update cloud.google.com/go/monitoring from 0.2.0 to 1.2.0
+- [#10536](https://github.com/influxdata/telegraf/pull/10536) Update github.com/vmware/govmomi from 0.26.0 to 0.27.2
+
+### New External Plugins
+
+- [apt](https://github.com/x70b1/telegraf-apt) - contributed by @x70b1
+- [knot](https://github.com/x70b1/telegraf-knot) - contributed by @x70b1
+
 ## v1.21.3 [2022-01-27]
 
 ### Bugfixes