[CLOUD-700] Fixed NPE

Author: douglaspalmer

common/src/main/java/org/openshift/ping/common/server/AbstractServer.java

@@ -86,7 +86,9 @@ private String getClusterName(final Channel channel) {
     }
 
     protected final void handlePingRequest(Channel channel, InputStream stream) throws Exception {
-        OpenshiftPing handler = (OpenshiftPing) channel.getProtocolStack().findProtocol(OpenshiftPing.class);
-        handler.handlePingRequest(stream);
+    	if (channel != null) {
+    		OpenshiftPing handler = (OpenshiftPing) channel.getProtocolStack().findProtocol(OpenshiftPing.class);
+            handler.handlePingRequest(stream);
+    	}
     }
 }