update config example

Author: wuriyanto48

config_example.json

@@ -51,7 +51,7 @@
 
         "kafka_cluster_one": {
             "kind": "kafka",
-            "url": "http://myname:mypassword@10.1.1.1:9093,10.1.1.2:9093,10.1.1.3:9093",
+            "url": "kafka://myname:mypassword@10.1.1.1:9093,10.1.1.2:9093,10.1.1.3:9093",
             "checkInterval": 5,
             "enable": true
         },