Cannot save plugin configuration

[lennartkoopmann]

When trying to save the AWS plugin configuration on the "Configurations" page I get a HTTP 400 with the following error in the graylog-server log:

2018-01-16T13:36:02.001-06:00 ERROR [ClusterConfigResource] Couldn't parse cluster configuration "org.graylog.aws.config.AWSPluginConfiguration".
com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "flowlogs_last_run" (class org.graylog.aws.config.AutoValue_AWSPluginConfiguration), not marked as ignorable (5 known properties: "secret_key", "lookup_regions", "lookups_enabled", "access_key", "proxy_enabled"])
 at [Source: org.glassfish.jersey.message.internal.EntityInputStream@1a5a0937; line: 1, column: 164] (through reference chain: org.graylog.aws.config.AutoValue_AWSPluginConfiguration["flowlogs_last_run"])
	at com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException.from(UnrecognizedPropertyException.java:62) ~[graylog.jar:?]
	at com.fasterxml.jackson.databind.DeserializationContext.handleUnknownProperty(DeserializationContext.java:834) ~[graylog.jar:?]
	at com.fasterxml.jackson.databind.deser.std.StdDeserializer.handleUnknownProperty(StdDeserializer.java:1093) ~[graylog.jar:?]
	at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.handleUnknownProperty(BeanDeserializerBase.java:1478) ~[graylog.jar:?]