Improve clustering thread pool validation

15:17:50,221 ERROR [org.jboss.msc.service.fail] (MSC service thread 1-6) MSC000001: Failed to start service jboss.jgroups.channel.ee: org.jboss.msc.service.StartException in service jboss.jgroups.channel.ee: java.lang.IllegalArgumentException
	at org.wildfly.clustering.jgroups.spi.service.ChannelBuilder.start(ChannelBuilder.java:80)
	at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1948)
	at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1881)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.IllegalArgumentException
	at java.util.concurrent.ThreadPoolExecutor.<init>(ThreadPoolExecutor.java:1307)
	at java.util.concurrent.ThreadPoolExecutor.<init>(ThreadPoolExecutor.java:1195)
	at org.jgroups.protocols.TP.createThreadPool(TP.java:2358)
	at org.jgroups.protocols.TP.init(TP.java:1152)
	at org.jgroups.protocols.BasicTCP.init(BasicTCP.java:87)
	at org.jgroups.stack.ProtocolStack.initProtocolStack(ProtocolStack.java:860)
	at org.jgroups.stack.ProtocolStack.setup(ProtocolStack.java:481)
	at org.jgroups.JChannel.init(JChannel.java:853)
	at org.jgroups.JChannel.<init>(JChannel.java:159)
	at org.jboss.as.clustering.jgroups.JChannelFactory$1.run(JChannelFactory.java:95)
	at org.jboss.as.clustering.jgroups.JChannelFactory$1.run(JChannelFactory.java:92)
	at org.wildfly.security.manager.WildFlySecurityManager.doChecked(WildFlySecurityManager.java:636)
	at org.jboss.as.clustering.jgroups.JChannelFactory.createChannel(JChannelFactory.java:98)
	at org.wildfly.clustering.jgroups.spi.service.ChannelBuilder.start(ChannelBuilder.java:78)
	... 5 more