update JS samples

Author: wing328

samples/client/petstore/javascript-es6/src/ApiClient.js

@@ -362,7 +362,7 @@ class ApiClient {
     * @param {Array.<String>} accepts An array of acceptable response MIME types.
     * @param {(String|Array|ObjectFunction)} returnType The required type to return; can be a string for simple types or the
     * constructor for a complex type.
-    * @param {String} apiBasePath base path defined in the operation/path level to override the default one 
+    * @param {String} apiBasePath base path defined in the operation/path level to override the default one
     * @param {module:ApiClient~callApiCallback} callback The callback function.
     * @returns {Object} The SuperAgent request object.
     */