Description of problem:
NullPointerException in JMSService.start which caused by referring to non-registered connector.

Version-Release number of selected component (if applicable):
2.3.0.CR1

Steps to Reproduce:
<connectors>
      <netty-connector name="netty" socket-binding="messaging"/>
      <netty-connector name="netty-throughput" socket-binding="messaging-throughput">
           <param key="batch-delay" value="50"/>
      </netty-connector>
<!--
      <netty-connector name="connector-to-proxy-directing-to-this-server" socket-binding="binding-connect-to-this-server-through-remote-proxy"/>
-->
      <in-vm-connector name="in-vm" server-id="0"/>
</connectors>

<broadcast-groups>
          <broadcast-group name="bg-group1">
          <socket-binding>messaging-group</socket-binding>
          <broadcast-period>2000</broadcast-period>
          <connector-ref>
             connector-to-proxy-directing-to-this-server
          </connector-ref>
      </broadcast-group>
</broadcast-groups>

Additional info:
15:56:47,200 WARN  [org.hornetq.core.server] (MSC service thread 1-5) HQ222185: There is no connector deployed with name {0}. The broadcast group with name {1} will not be deployed.
15:56:47,201 ERROR [org.hornetq.core.server] (MSC service thread 1-5) HQ224002: Failure in initialisation: java.lang.NullPointerException
	at org.hornetq.core.server.management.impl.ManagementServiceImpl.registerBroadcastGroup(ManagementServiceImpl.java:346) [hornetq-server-2.3.0.CR1.jar:]
	at org.hornetq.core.server.cluster.ClusterManager.deployBroadcastGroup(ClusterManager.java:815) [hornetq-server-2.3.0.CR1.jar:]
	at org.hornetq.core.server.cluster.ClusterManager.deploy(ClusterManager.java:225) [hornetq-server-2.3.0.CR1.jar:]
	at org.hornetq.core.server.impl.HornetQServerImpl.initialisePart1(HornetQServerImpl.java:1414) [hornetq-server-2.3.0.CR1.jar:]
	at org.hornetq.core.server.impl.HornetQServerImpl.access$1000(HornetQServerImpl.java:164) [hornetq-server-2.3.0.CR1.jar:]
	at org.hornetq.core.server.impl.HornetQServerImpl$SharedNothingLiveActivation.run(HornetQServerImpl.java:2496) [hornetq-server-2.3.0.CR1.jar:]
	at org.hornetq.core.server.impl.HornetQServerImpl.start(HornetQServerImpl.java:416) [hornetq-server-2.3.0.CR1.jar:]
	at org.hornetq.jms.server.impl.JMSServerManagerImpl.start(JMSServerManagerImpl.java:464) [hornetq-jms-server-2.3.0.CR1.jar:]
	at org.jboss.as.messaging.jms.JMSService.start(JMSService.java:74) [jboss-as-messaging-7.2.0.Alpha1-redhat-4.jar:7.2.0.Alpha1-redhat-4]
	at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1811) [jboss-msc-1.0.4.GA.jar:1.0.4.GA]
	at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1746) [jboss-msc-1.0.4.GA.jar:1.0.4.GA]
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) [rt.jar:1.6.0_38]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) [rt.jar:1.6.0_38]
	at java.lang.Thread.run(Thread.java:662) [rt.jar:1.6.0_38]

15:56:47,205 ERROR [org.jboss.msc.service.fail] (MSC service thread 1-5) MSC00001: Failed to start service jboss.messaging.default.jms.manager: org.jboss.msc.service.StartException in service jboss.messaging.default.jms.manager: java.lang.NullPointerException
	at org.jboss.as.messaging.jms.JMSService.start(JMSService.java:97)
	at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1811) [jboss-msc-1.0.4.GA.jar:1.0.4.GA]
	at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1746) [jboss-msc-1.0.4.GA.jar:1.0.4.GA]
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) [rt.jar:1.6.0_38]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) [rt.jar:1.6.0_38]
	at java.lang.Thread.run(Thread.java:662) [rt.jar:1.6.0_38]
Caused by: java.lang.NullPointerException
	at org.jboss.as.messaging.jms.JMSService.start(JMSService.java:78)
	... 5 more