Bug 1760604 - fix bogus domain to be example.com which is part of our test PAC rules. r=ahal

Differential Revision: https://phabricator.services.mozilla.com/D141609

dom/base/test/test_bug338583.html

@@ -338,7 +338,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=338583
   }
 
   function doTest3_g(test_id) {
-    gEventSourceObj3_g = new EventSource("http://hdfskjghsbg.jtiyoejowe.dafsgbhjab.com");
+    gEventSourceObj3_g = new EventSource("http://hdfskjghsbg.jtiyoejowe.example.com");
 
     gEventSourceObj3_g.onmessage = fn_onmessage;
     gEventSourceObj3_g.hits = [];