Change the copy of the success message

These changes were suggested by Ryan Feeley:

2cf911cc32 (commitcomment-4614712)

index.html

@@ -166,7 +166,7 @@ body.loading a span:after  { display: none; }
 <a id="auth"><img src="data:image/gif;base64,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" alt="Progress indicator" height="16" width="16"><span>Sign in with your email</span></a>
 </div>
 <div id="victory" style="display: none;">
-  Congratulations!  You're ready to sign in with your email address!
+  Congratulations! You just did what it takes to log in to a site that provides a Persona-based sign-in.
 </div>
 <script>