test.html: don't stringify response from server for more readable output dumps sans escaped quotes

public/test.html

@@ -13,7 +13,7 @@
           }
           let responseDumpElt = document.getElementById("responseDump");
           responseDumpElt.appendChild(
-            document.createTextNode(JSON.stringify(xhr.response)));
+            document.createTextNode(xhr.response));
           responseDumpElt.appendChild(
             document.createElement("hr"));
           responseDumpElt.appendChild(