Catch systemexit from kibana

lib/logstash/kibana.rb

@@ -80,7 +80,13 @@ module LogStash::Kibana
         #end
       end
 
-      args = opts.parse(args)
+      begin
+        args = opts.parse(args)
+      rescue SystemExit
+        # if you ask for --help, optparse will exit.
+        # capture it and return normally
+        return []
+      end
 
       @thread = Thread.new do
         Cabin::Channel.get.info("Starting web server", :settings => settings)
@@ -94,7 +100,7 @@ module LogStash::Kibana
 
     public
     def wait
-      @thread.join
+      @thread.join if @thread
       return 0
     end # def wait
   end