Fix xhr.responseType set before xhr.open

Author: bmpvieira

lib/request.js

@@ -21,16 +21,16 @@ var Request = module.exports = function (xhr, params) {
 
     try { xhr.withCredentials = params.withCredentials }
     catch (e) {}
-    
-    if (params.responseType) try { xhr.responseType = params.responseType }
-    catch (e) {}
-    
+
     xhr.open(
         params.method || 'GET',
         self.uri,
         true
     );
 
+    if (params.responseType) try { xhr.responseType = params.responseType }
+    catch (e) {}
+
     self._headers = {};
 
     if (params.headers) {