Update app scheme target to spreadprivacy. (#194)

duckduckgo.com has too frequent updates/experiments that affect our test assertions.

security/address-bar-spoofing/spoof-application-scheme.html

@@ -18,9 +18,9 @@
     <p><a href="./index.html">[Back]</a></p>
     This test uses an unsupported application scheme and a href target to trick the browser into displaying the href
     target as the current address bar value, while actually navigating to an attacker controlled page.
-    <a id="run" href="https://duckduckgo.com:" target="aa" onclick="setTimeout('run()',100)">
+    <a id="run" href="https://spreadprivacy.com:" target="aa" onclick="setTimeout('run()',100)">
         <h1>Start</h1>
     </a>
 </body>
 
-</html>
+</html>