Modifying the recursive sprintf map to be similar to the current impl…

…ementation

lib/logstash/outputs/slack.rb

@@ -40,7 +40,7 @@ def register
   def recursive_sprintf(event, node)
     case node
       when String
-        node = event.sprintf(node)
+        node = JSON.parse(event.sprintf(JSON.dump(node)))
       when Array
         node.map! do |obj|
           recursive_sprintf( event, obj )
@@ -78,7 +78,8 @@ def receive(event)
     end
 
     if @attachments and @attachments.any?
-      payload_json['attachments'] = recursive_sprintf(event , @attachments)
+     payload_json['attachments'] = @attachments.map { |x| recursive_sprintf(event, x) }
+   # payload_json['attachments'] = recursive_sprintf(event , @attachments)
     end
     if event.include?('attachments') and event.get('attachments').is_a?(Array)
       if event.get('attachments').any?