Update locationQuery to take location as second parameter

Author: kivutar

graphiql.go

@@ -148,10 +148,8 @@ add "&raw" to the end of the URL within a browser.
     });
 
     // Produce a Location query string from a parameter object.
-    function locationQuery(params) {
-      return '?' + Object.keys(params).filter(function (key) {
-        return Boolean(params[key]);
-      }).map(function (key) {
+    function locationQuery(params, location) {
+      return (location ? location: '') + '?' + Object.keys(params).map(function (key) {
         return encodeURIComponent(key) + '=' +
           encodeURIComponent(params[key]);
       }).join('&');