ARTEMIS-652 Incorrect null check in ActiveMQActivationSpec#toString f…

…or attribute connectionFactoryLookup

Changed null check to check correct attribute

(cherry picked from commit d281eb5)

https://issues.jboss.org/browse/JBEAP-5394

artemis-ra/src/main/java/org/apache/activemq/artemis/ra/inflow/ActiveMQActivationSpec.java

@@ -761,7 +761,7 @@ public String toString() {
       StringBuffer buffer = new StringBuffer();
       buffer.append(ActiveMQActivationSpec.class.getName()).append('(');
       buffer.append("ra=").append(ra);
-      if (messageSelector != null) {
+      if (connectionFactoryLookup != null) {
          buffer.append(" connectionFactoryLookup=").append(connectionFactoryLookup);
       }
       buffer.append(" destination=").append(destination);