Merge pull request newrelic#21 from loe/master

Correct the ActiveMessaging Instrumentation to actually work

lib/rpm_contrib/instrumentation/active_messaging.rb

@@ -1,24 +1,22 @@
-# == ActiveMessaging Instrumentation ==
-# Robert R. Meyer
-# Blue-Dog-Archolite @ GitHub
+# ActiveMessaging Instrumentation
 
 DependencyDetection.defer do
   @name = :active_messaging
-  
+
   depends_on do
     defined?(::ActiveMessaging::Processor) && !NewRelic::Control.instance['disable_active_messaging'] &&
       !NewRelic::Control.instance['disable_active_mq']
   end
-  
+
   executes do
     NewRelic::Agent.logger.debug 'Installing ActiveMessaging instrumentation'
   end
 
   executes do
     ::ActiveMessaging::Processor.class_eval do
-      class << self
-        add_method_tracer :on_message, 'ActiveMessaging/OnMessage'
-      end
+      include NewRelic::Agent::MethodTracer
+
+      add_method_tracer :on_message, 'ActiveMessaging/OnMessage'
     end
   end
 end