Move iframe onload handler setup later to avoid initial about:blank onload event.

toolkit/components/passwordmgr/test/test_prompt.html

@@ -394,9 +394,6 @@ var authinfo = {
 };
 
 
-var iframe = document.getElementById("iframe");
-iframe.onload = handleLoad;
-
 var prompter1 = promptFac.getPrompt(window, Ci.nsIAuthPrompt);
 var prompter2 = promptFac.getPrompt(window, Ci.nsIAuthPrompt2);
 
@@ -709,6 +706,10 @@ is(authinfo.password, "user2pass", "Checking returned password");
 // XXX check NTLM domain stuff
 
 
+var iframe = document.getElementById("iframe");
+iframe.onload = handleLoad;
+
+
 // ===== test 1000 =====
 testNum = 1000;
 startCallbackTimer();