Merge pull request AsyncHttpClient#43 from pkulak/patch-2

This fixes a bug I _just_ introduced with my last pull request.

Author: jfarcand

src/main/java/com/ning/http/util/AsyncHttpProviderUtils.java

@@ -432,7 +432,7 @@ public static String parseCharset(String contentType) {
         for (String part : contentType.split(";")) {
             if (part.trim().startsWith("charset=")) {
                 String[] val = part.split("=");
-                if (val[1].length > 1) {
+                if (val.length > 1) {
                     return val[1].trim();
                 }
             }