fix: typo on accessing arguments variable for parameter check

lib/api/event.js

@@ -118,7 +118,7 @@ function get(eventId, callback){
  *  ```
  */
 function query(start, end, parameters, callback){
-    if(arguments.length < 4 && typeof argument[2] === "function"){
+    if(arguments.length < 4 && typeof arguments[2] === "function"){
         callback = parameters;
         parameters = {};
     }