dispatch: fix race condition in dispatch test (#1025)
dispatch: fix race condition in dispatch test (#1025)


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