remove the use of throwable.getCause in ThrowableCreatedElsewhere. It's useless, because we can only use this thing when there's no cause

Author: David R. MacIver

src/com/rabbitmq/utility/Utility.java

@@ -41,7 +41,7 @@
 public class Utility {
     static class ThrowableCreatedElsewhere extends Throwable{
         public ThrowableCreatedElsewhere(Throwable throwable){
-          super(throwable.getClass() + " created elsewhere", throwable.getCause());
+          super(throwable.getClass() + " created elsewhere");
           this.setStackTrace(throwable.getStackTrace());
         }