Fixing NPE on Kafka consumer

NullPointerException during initialization 

java.lang.NullPointerException: null at org.kie.server.services.jbpm.kafka.KafkaServerConsumer.registrationUpdated(KafkaServerConsumer.java:126) ~[*kie-server-services-kafka-7.57.0-SNAPSHOT.jar!/:7.57.0-SNAPSHOT*] at org.kie.server.services.jbpm.kafka.KafkaServerConsumer.removeRegistration(KafkaServerConsumer.java:85) ~[kie-server-services-kafka-7.57.0-SNAPSHOT.jar!/:7.57.0-SNAPSHOT] at org.kie.server.services.jbpm.kafka.KafkaServerExtension.onUnDeploy(KafkaServerExtension.java:166) ~[kie-server-services-kafka-7.57.0-SNAPSHOT.jar!/:7.57.0-SNAPSHOT] at org.jbpm.kie.services.impl.AbstractDeploymentService.notifyOnUnDeploy(AbstractDeploymentService.java:101) ~[jbpm-kie-services-7.57.0-SNAPSHOT.jar!/:7.57.0-SNAPSHOT] at org.jbpm.kie.services.impl.AbstractDeploymentService.commonDeploy(AbstractDeploymentService.java:169) ~[jbpm-kie-services-7.57.0-SNAPSHOT.jar!/:7.57.0-SNAPSHOT]