[...]/src/main/java/org/graylog/plugins/internallogs/log4j/DirectConsumingAppender.java:25: warning: [deprecation] SerializedLayout in org.apache.logging.log4j.core.layout has been deprecated
import org.apache.logging.log4j.core.layout.SerializedLayout;
https://issues.apache.org/jira/browse/LOG4J2-1958