Fixes android-async-http#194

Author: smarek

library/src/com/loopj/android/http/AsyncHttpClient.java

@@ -687,7 +687,7 @@ protected void sendRequest(DefaultHttpClient client, HttpContext httpContext, Ht
     public static String getUrlWithQueryString(String url, RequestParams params) {
         if (params != null) {
             String paramString = params.getParamString();
-            if (url.indexOf("?") == -1) {
+            if (!url.contains("?")) {
                 url += "?" + paramString;
             } else {
                 url += "&" + paramString;