Use for..of instead of array loop (#408)

Use Header.entries() returns an iterator not necessarily an Array.

See https://developer.mozilla.org/en-US/docs/Web/API/Headers/entries

lib/html/includes.js

@@ -851,8 +851,7 @@ var MiniProfiler = (function() {
           try {
             // look for x-mini-profile-ids
             var entries = response.headers.entries();
-            for (var i = 0; i < entries.length; i++) {
-              var pair = entries[i];
+            for (var pair of entries) {
               if (pair[0] && pair[0].toLowerCase() == "x-miniprofiler-ids") {
                 var ids = pair[1].split(",");
                 fetchResults(ids);