fix issue where result was also top level in returned json

mobile.webservice.php

@@ -30,8 +30,8 @@ abstract class WebService
         $data = array();
 
         try {
-            $data = $this->Call();
-            $data["result"][$this->func] = $data;
+            $result = $this->Call();
+            $data["result"][$this->func] = $result;
         } catch (WebException $e) {
             $data["error"]["code"] = $e->getCode();
             $data["error"]["name"] = $e->getName();