Undertow does not shut down properly in webhook route policy

[nicolaferraro]

After #171, the undertow compnent does not shut down properly during tests. Exception is ignored, but worth investigating:

2019-10-23 16:49:12.650|WARN |Camel (camel-k) thread #3 - terminator|org.apache.camel.impl.DefaultCamelContext - Error occurred while shutting down service: org.apache.camel.impl.RouteService@4d550e4a. This exception will be ignored.
org.apache.camel.RuntimeCamelException: java.lang.NullPointerException
	at org.apache.camel.RuntimeCamelException.wrapRuntimeCamelException(RuntimeCamelException.java:52) ~[camel-api-3.0.0-RC1.jar:3.0.0-RC1]
	at org.apache.camel.support.ChildServiceSupport.stop(ChildServiceSupport.java:89) ~[camel-support-3.0.0-RC1.jar:3.0.0-RC1]
	at org.apache.camel.support.service.ServiceHelper.stopService(ServiceHelper.java:120) ~[camel-api-3.0.0-RC1.jar:3.0.0-RC1]
	at org.apache.camel.support.service.ServiceHelper.stopAndShutdownService(ServiceHelper.java:185) ~[camel-api-3.0.0-RC1.jar:3.0.0-RC1]
	at org.apache.camel.impl.engine.AbstractCamelContext.shutdownServices(AbstractCamelContext.java:2857) ~[camel-base-3.0.0-RC1.jar:3.0.0-RC1]
	at org.apache.camel.impl.engine.AbstractCamelContext.shutdownServices(AbstractCamelContext.java:2882) ~[camel-base-3.0.0-RC1.jar:3.0.0-RC1]
	at org.apache.camel.impl.engine.AbstractCamelContext.doStop(AbstractCamelContext.java:2704) ~[camel-base-3.0.0-RC1.jar:3.0.0-RC1]
	at org.apache.camel.support.service.ServiceSupport.stop(ServiceSupport.java:141) ~[camel-api-3.0.0-RC1.jar:3.0.0-RC1]
	at org.apache.camel.impl.engine.AbstractCamelContext.stop(AbstractCamelContext.java:2407) ~[camel-base-3.0.0-RC1.jar:3.0.0-RC1]
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_181]
Caused by: java.lang.NullPointerException
	at org.apache.camel.component.undertow.UndertowComponent.unregisterEndpoint(UndertowComponent.java:346) ~[camel-undertow-3.0.0-RC1.jar:3.0.0-RC1]
	at org.apache.camel.component.undertow.UndertowConsumer.doStop(UndertowConsumer.java:114) ~[camel-undertow-3.0.0-RC1.jar:3.0.0-RC1]
	at org.apache.camel.support.service.ServiceSupport.stop(ServiceSupport.java:141) ~[camel-api-3.0.0-RC1.jar:3.0.0-RC1]
	at org.apache.camel.support.service.ServiceHelper.stopService(ServiceHelper.java:120) ~[camel-api-3.0.0-RC1.jar:3.0.0-RC1]
	at org.apache.camel.component.webhook.MultiRestConsumer.doStop(MultiRestConsumer.java:79) ~[camel-webhook-3.0.0-RC1.jar:3.0.0-RC1]
	at org.apache.camel.support.service.ServiceSupport.stop(ServiceSupport.java:141) ~[camel-api-3.0.0-RC1.jar:3.0.0-RC1]
	at org.apache.camel.support.service.ServiceHelper.stopService(ServiceHelper.java:120) ~[camel-api-3.0.0-RC1.jar:3.0.0-RC1]
	at org.apache.camel.support.service.ServiceHelper.stopAndShutdownService(ServiceHelper.java:185) ~[camel-api-3.0.0-RC1.jar:3.0.0-RC1]
	at org.apache.camel.impl.engine.BaseRouteService.stopChildService(BaseRouteService.java:356) ~[camel-base-3.0.0-RC1.jar:3.0.0-RC1]
	at org.apache.camel.impl.engine.BaseRouteService.doStop(BaseRouteService.java:240) ~[camel-base-3.0.0-RC1.jar:3.0.0-RC1]
	at org.apache.camel.support.ChildServiceSupport.stop(ChildServiceSupport.java:82) ~[camel-support-3.0.0-RC1.jar:3.0.0-RC1]
	... 8 more
2019-10-23 16:49:12.657|INFO |Camel (camel-k) thread #3 - terminator|org.apache.camel.main.MainLifecycleStrategy - CamelContext: camel-k has been shutdown, triggering shutdown of the JVM.