NPE when microprofile-metrics subsystem is enabled but microprofile-config is not

2019-09-11 17:49:43,522 ERROR [org.jboss.as.controller.management-operation] (Controller Boot Thread) WFLYCTL0013: Operation ("add") failed - address: ([("subsystem" => "microprofile-metrics-smallrye")]): java.lang.NullPointerException
	at org.wildfly.extension.microprofile.metrics.MicroProfileMetricsSubsystemAdd$2.execute(MicroProfileMetricsSubsystemAdd.java:90)
	at org.jboss.as.controller.AbstractOperationContext.executeStep(AbstractOperationContext.java:999) [wildfly-controller-9.0.2.Final.jar:9.0.2.Final]
	at org.jboss.as.controller.AbstractOperationContext.processStages(AbstractOperationContext.java:743) [wildfly-controller-9.0.2.Final.jar:9.0.2.Final]
	at org.jboss.as.controller.AbstractOperationContext.executeOperation(AbstractOperationContext.java:467) [wildfly-controller-9.0.2.Final.jar:9.0.2.Final]
	at org.jboss.as.controller.OperationContextImpl.executeOperation(OperationContextImpl.java:1412) [wildfly-controller-9.0.2.Final.jar:9.0.2.Final]
	at org.jboss.as.controller.ModelControllerImpl.boot(ModelControllerImpl.java:521) [wildfly-controller-9.0.2.Final.jar:9.0.2.Final]
	at org.jboss.as.controller.AbstractControllerService.boot(AbstractControllerService.java:472) [wildfly-controller-9.0.2.Final.jar:9.0.2.Final]
	at org.jboss.as.controller.AbstractControllerService.boot(AbstractControllerService.java:434) [wildfly-controller-9.0.2.Final.jar:9.0.2.Final]
	at org.jboss.as.server.ServerService.boot(ServerService.java:435) [wildfly-server-9.0.2.Final.jar:9.0.2.Final]
	at org.jboss.as.server.ServerService.boot(ServerService.java:394) [wildfly-server-9.0.2.Final.jar:9.0.2.Final]
	at org.jboss.as.controller.AbstractControllerService$1.run(AbstractControllerService.java:374) [wildfly-controller-9.0.2.Final.jar:9.0.2.Final]
	at java.lang.Thread.run(Thread.java:748) [rt.jar:1.8.0_212]