Correct CHANGELOG.md
Correct CHANGELOG.md

prometheus/alertmanager,Kellel/alertmanager,prometheus/alertmanager,GoogleCloudPlatform/alertmanager,GoogleCloudPlatform/alertmanager,prometheus/alertmanager,tyrken/alertmanager,tyrken/alertmanager,Aloomaio/alertmanager,Kellel/alertmanager,GoogleCloudPlatform/alertmanager,tyrken/alertmanager,Aloomaio/alertmanager,tyrken/alertmanager,prometheus/alertmanager,Aloomaio/alertmanager,GoogleCloudPlatform/alertmanager,Kellel/alertmanager